WorldWideScience

Sample records for wireless optical link

  1. Achievable qualitative parameters of optical wireless links

    Czech Academy of Sciences Publication Activity Database

    Kolka, Z.; Wilfert, O.; Fišer, Ondřej

    2007-01-01

    Roč. 9, č. 8 (2007), s. 2419-2423 ISSN 1454-4164 R&D Projects: GA ČR(CZ) GA102/05/0571 Institutional research plan: CEZ:AV0Z30420517 Keywords : Free-space optical link * Transmission of atmosphere * Optical communication Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.827, year: 2007 http://inoe.inoe.ro/joam/index.php?option=magazine&op=view&idu=838&catid=16

  2. Optical wireless links with enhanced linearity and selectivity [Invited

    Science.gov (United States)

    Green, Roger J.; Sweet, C.; Idrus, S.

    2005-10-01

    Optical wireless is an attractive medium as an alternative to optical fiber communications, and also to RF, because of its high bandwidth and relative ease of use, especially when it comes to deployment in new physical situations. We describe an optical wireless link approach that offers a performance that gives analog transmission with significantly reduced distortion levels and enhanced reception sensitivity by combining a novel hybrid detector-amplifier technique. Reduction of distortion by 40 dB and improvement in sensitivity of 20-30 dB is possible, using the techniques described.

  3. Imaging and steering an optical wireless nanoantenna link.

    Science.gov (United States)

    Dregely, Daniel; Lindfors, Klas; Lippitz, Markus; Engheta, Nader; Totzeck, Michael; Giessen, Harald

    2014-07-04

    Optical nanoantennas tailor the transmission and reception of optical signals. Owing to their capacity to control the direction and angular distribution of optical radiation over a broad spectral range, nanoantennas are promising components for optical communication in nanocircuits. Here we measure wireless optical power transfer between plasmonic nanoantennas in the far-field and demonstrate changeable signal routing to different nanoscopic receivers via beamsteering. We image the radiation pattern of single-optical nanoantennas using a photoluminescence technique, which allows mapping of the unperturbed intensity distribution around plasmonic structures. We quantify the distance dependence of the power transmission between transmitter and receiver by deterministically positioning nanoscopic fluorescent receivers around the transmitting nanoantenna. By adjusting the wavefront of the optical field incident on the transmitter, we achieve directional control of the transmitted radiation over a broad range of 29°. This enables wireless power transfer from one transmitter to different receivers.

  4. Quantum-classical access networks with embedded optical wireless links

    Science.gov (United States)

    Elmabrok, Osama; Ghalaii, Masoud; Razavi, Mohsen

    2018-03-01

    We examine the applicability of wireless indoor quantum key distribution (QKD) in hybrid quantum-classical networks. We propose practical configurations that would enable wireless access to such networks. The proposed setups would allow an indoor wireless user, equipped with a QKD-enabled mobile device, to communicate securely with a remote party on the other end of the access network. QKD signals, sent through wireless indoor channels, are combined with classical ones and sent over shared fiber links to the remote user. Dense wavelengthdivision multiplexing would enable the simultaneous transmission of quantum and classical signals over the same fiber. We consider the adverse effects of the background noise induced by Raman scattered light on the QKD receivers due to such an integration. In addition, we consider the loss and the background noise that arise from indoor environments. We consider a number of discrete and continuous-variable QKD protocols and study their performance in different scenarios.

  5. Impact of Various Parameters on the Performance of Inter-aircraft Optical Wireless Communication Link

    Science.gov (United States)

    Singh, Mehtab

    2017-12-01

    Optical wireless communication (OWC) systems also known as Free space optics (FSO) are capable of providing high channel bandwidth, high data transmission rates, low power consumption, and high security. OWC links are being considered in different applications such as inter-satellite links, terrestrial links, and inter-aircraft communication links. This paper investigates the impact of different system parameters such as transmission power level, operating wavelength, transmitter pointing error angle, bit transmission rate, atmospheric attenuation, antenna aperture diameter, geometric losses, the responsivity of the photodetector, and link range on the performance of inter-aircraft optical wireless communication link.

  6. Optical coherent and envelope detection for photonic wireless communication links

    DEFF Research Database (Denmark)

    Prince, Kamau; Zibar, Darko; Yu, Xianbin

    We present two novel optical detection techniques for radio over fiber (RoF) communication links. Firstly, we present recent results obtained with optical digital coherent detection of optical phase-modulated ROF signals supporting error-free transmission over 25 km standard SMF with BPSK and QPSK...

  7. Enhanced Performance Analysis of Inter-aircraft Optical Wireless Communication Link Using Array of Photodetectors

    Science.gov (United States)

    Singh, Mehtab

    2017-12-01

    This paper investigates the impact of various parameters on the performance of inter-aircraft optical wireless communication (IaOWC) link. Also, an improved performance analysis of a 2.5 Gbps IaOWC link using an array of photodetectors at the receiver terminal has been reported. The results show an increase in the SNR and total power of the received signal at a link distance of 100 km by deploying a photodetector array at the receiver terminal.

  8. Channel capacity study of underwater wireless optical communications links based on Monte Carlo simulation

    International Nuclear Information System (INIS)

    Li, Jing; Ma, Yong; Zhou, Qunqun; Zhou, Bo; Wang, Hongyuan

    2012-01-01

    Channel capacity of ocean water is limited by propagation distance and optical properties. Previous studies on this problem are based on water-tank experiments with different amounts of Maalox antacid. However, propagation distance is limited by the experimental set-up and the optical properties are different from ocean water. Therefore, the experiment result is not accurate for the physical design of underwater wireless communications links. This letter developed a Monte Carlo model to study channel capacity of underwater optical communications. Moreover, this model can flexibly configure various parameters of transmitter, receiver and channel, and is suitable for physical underwater optical communications links design. (paper)

  9. Channel capacity study of underwater wireless optical communications links based on Monte Carlo simulation

    Science.gov (United States)

    Li, Jing; Ma, Yong; Zhou, Qunqun; Zhou, Bo; Wang, Hongyuan

    2012-01-01

    Channel capacity of ocean water is limited by propagation distance and optical properties. Previous studies on this problem are based on water-tank experiments with different amounts of Maalox antacid. However, propagation distance is limited by the experimental set-up and the optical properties are different from ocean water. Therefore, the experiment result is not accurate for the physical design of underwater wireless communications links. This letter developed a Monte Carlo model to study channel capacity of underwater optical communications. Moreover, this model can flexibly configure various parameters of transmitter, receiver and channel, and is suitable for physical underwater optical communications links design.

  10. Investigation of solar noise impact on the performance of underwater wireless optical communication links

    OpenAIRE

    Hamza, Tasnim; Khalighi, Mohammad-ali; Bourennane, Salah; Leon, Pierre; Opderbecke, Jan

    2016-01-01

    We investigate the effect of environmental noise, caused by solar radiations under water, on the performance of underwater wireless optical communication (UWOC) systems. Presenting an analytical and generic model for this noise, we examine its impact on the link performance in terms of the bit error rate (BER). This study is conducted for different photo-detector types in the aim of highlighting practical limitations of establishing UWOC links in the presence of subsea solar noise. We show ho...

  11. Modeling and Performance Analysis of 10 Gbps Inter-satellite Optical Wireless Communication Link

    Science.gov (United States)

    Singh, Mehtab

    2017-12-01

    Free-space optical (FSO) communication has the advantages of two of the most predominant data transmission technologies - optical fiber communication and wireless communication. Most of the technical aspects of FSO are similar to that of optical fiber communication, with major difference in the information signal propagation medium which is free space in case of FSO rather than silica glass in optical fiber communication. One of the most important applications of FSO is inter-satellite optical wireless communication (IsOWC) links which will be deployed in the future in space. The IsOWC links have many advantages over the previously existing microwave satellite communication technologies such as higher bandwidth, lower power consumption, low cost of implementation, light size, and weight. In this paper, modeling and performance analysis of a 10-Gbps inter-satellite communication link with two satellites separated at a distance of 1,200 km has been done using OPTISYSTEM simulation software. Performance has been analyzed on the basis of quality factor, signal to noise ratio (SNR), and total power of the received signal.

  12. Opportunities and challenges for optical wireless: the competitive advantage of free space telecommunications links in today's crowded marketplace

    Science.gov (United States)

    Carbonneau, Theresa H.; Wisely, David R.

    1998-01-01

    Never before has the opportunity for terrestrial optical wireless communications links been so great. The high data rates attainable, up to OC-24, make it a very attractive and cost effective alternative to traditional fiber optic and microwave links. With today's demand for interactive multimedia-based applications, such as video conferencing and telemedicine, optical wireless products are the only ones that can provide the needed bandwidth in situations when it is too costly or impossible to install fiber optic cable. Recent developments in laser and optics technologies, in addition to auto beam tracking, permit transmission units to achieve excellent performance rates in all weather conditions.

  13. Converged wireline and wireless signal transport over optical fibre access links

    DEFF Research Database (Denmark)

    Tafur Monroy, Idelfonso; Prince, Kamau; Osadchiy, Alexey Vladimirovich

    2009-01-01

    This article reviews emerging trends in converged optical-wireless communication systems and outline the role that photonic technologies are playing in making the vision of a wireline-wireless converged signal transport network a reality.......This article reviews emerging trends in converged optical-wireless communication systems and outline the role that photonic technologies are playing in making the vision of a wireline-wireless converged signal transport network a reality....

  14. Digital Photonic Receivers for Wireless and Wireline Optical Fiber Transmission Links

    DEFF Research Database (Denmark)

    Guerrero Gonzalez, Neil

    This PhD thesis addresses the design and performance evaluation of digital photonic receivers in hybrid optical fiber-wireless transmission systems. The research results presented in this thesis are pioneering in two areas. First, it is shown the first experimental demonstration of automatic...... demodulation of signals with mixed modulation formats and bit rates in a single digital coherent photonic receiver. The demodulated signals were generated on baseband and optical phase-modulated (PM) radio-over-fiber (RoF) systems. Secondly, it is presented the first known analytical and numerical...... investigations on the performance of data-aided optical channel estimation based on constant-amplitude zero-autocorrelation (CAZAC) sequences for 112 Gb/s polarization-diversity coherent optical fiber transmission links. The benefits of introducing digital signal processing functions in optically envelope...

  15. Hybrid Optical Fibre-wireless Links at the 75-110 GHz Band Supporting 100 Gbps Transmission Capacities

    DEFF Research Database (Denmark)

    Zibar, Darko; Caballero Jambrina, Antonio; Yu, Xianbin

    2011-01-01

    We present a photonic generation and downconversion method for realizing a 40Gbps wireless link at the 75-110 GHz band exploiting the recent advances in photonic coherent detection technologies and digital signal processing. Furthermore, we analyze the capacities of hybrid optical fiber-wireless ......We present a photonic generation and downconversion method for realizing a 40Gbps wireless link at the 75-110 GHz band exploiting the recent advances in photonic coherent detection technologies and digital signal processing. Furthermore, we analyze the capacities of hybrid optical fiber...

  16. Performance Evaluation of Underwater Wireless Optical Communications Links in the Presence of Different Air Bubble Populations

    KAUST Repository

    Oubei, Hassan M.

    2017-03-16

    We experimentally evaluate the performance of underwater wireless optical communication (UWOC) links in the presence of different air bubbles. Air bubbles of different sizes and densities are generated by using an air pipe in conjunction with a submersible water pump of variable flow rate that help break up large bubbles into smaller bubbles. Received signal intensity measurements show that bubbles significantly degrade the performance of UWOC links. Large bubbles completely obstruct the optical beam and cause a deep fade. However, as the bubble size decreases, the level of deep fade also decreases because the optical beam is less susceptible to complete obstruction and more light reaches the detector. We also show that beam expansion could help mitigate the performance degradation due to the deep fade caused by air bubbles scatters in the channel.

  17. 20-meter underwater wireless optical communication link with 15 Gbps data rate

    KAUST Repository

    Shen, Chao

    2016-10-24

    The video streaming, data transmission, and remote control in underwater call for high speed (Gbps) communication link with a long channel length (∼10 meters). We present a compact and low power consumption underwater wireless optical communication (UWOC) system utilizing a 450-nm laser diode (LD) and a Si avalanche photodetector. With the LD operating at a driving current of 80 mA with an optical power of 51.3 mW, we demonstrated a high-speed UWOC link offering a data rate up to 2 Gbps over a 12-meter-long, and 1.5 Gbps over a record 20-meter-long underwater channel. The measured bit-error rate (BER) are 2.8 × 10-5, and 3.0 × 10-3, respectively, which pass well the forward error correction (FEC) criterion. © 2016 Optical Society of America.

  18. Investigation of solar noise impact on the performance of underwater wireless optical communication links.

    Science.gov (United States)

    Hamza, Tasnim; Khalighi, Mohammad-Ali; Bourennane, Salah; Léon, Pierre; Opderbecke, Jan

    2016-10-31

    We investigate the effect of environmental noise, caused by solar radiations under water, on the performance of underwater wireless optical communication (UWOC) systems. Presenting an analytical and generic model for this noise, we examine its impact on the link performance in terms of the bit error rate (BER). This study is conducted for different photo-detector types in the aim of highlighting practical limitations of establishing UWOC links in the presence of subsea solar noise. We show how the solar noise can impact the performance of UWOC links for relatively low operation depths. The results we present provide valuable insight for the design of UWOC links, which are likely to be established at relatively low depths. They can be exploited not only for the purpose of practical UWOC system deployment but also for in-pool experimental set-ups, since they elucidate the effect of ambient light on the measurements.

  19. 20-meter underwater wireless optical communication link with 1.5 Gbps data rate.

    Science.gov (United States)

    Shen, Chao; Guo, Yujian; Oubei, Hassan M; Ng, Tien Khee; Liu, Guangyu; Park, Ki-Hong; Ho, Kang-Ting; Alouini, Mohamed-Slim; Ooi, Boon S

    2016-10-31

    The video streaming, data transmission, and remote control in underwater call for high speed (Gbps) communication link with a long channel length (~10 meters). We present a compact and low power consumption underwater wireless optical communication (UWOC) system utilizing a 450-nm laser diode (LD) and a Si avalanche photodetector. With the LD operating at a driving current of 80 mA with an optical power of 51.3 mW, we demonstrated a high-speed UWOC link offering a data rate up to 2 Gbps over a 12-meter-long, and 1.5 Gbps over a record 20-meter-long underwater channel. The measured bit-error rate (BER) are 2.8 × 10-5, and 3.0 × 10-3, respectively, which pass well the forward error correction (FEC) criterion.

  20. 100 Gbit/s hybrid optical fiber-wireless link in the W-band (75–110 GHz)

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Caballero Jambrina, Antonio; Dogadaev, Anton Konstantinovich

    2011-01-01

    We experimentally demonstrate an 100 Gbit/s hybrid optical fiber-wireless link by employing photonic heterodyning up-conversion of optical 12.5 Gbaud polarization multiplexed 16-QAM baseband signal with two free running lasers. Bit-error-rate performance below the FEC limit is successfully achieved...... for air transmission distances up to 120 cm....

  1. Data transmission techniques for short-range optical fiber and wireless communication links

    DEFF Research Database (Denmark)

    Pham, Tien Thang

    -speed optical/wireless integration and advanced modulation formats for intensity modulation with direct detection (IM/DD) optical systems. Regarding optical/wireless integration, this thesis focuses on integration of broadband ultra-wide band (UWB) and 60-GHz band wireless systems into optical fiber access...... signals into a unified optical fiber platform. Additionally, half-cycle QAM modulation has prospects to increase SE and bit rates in high-speed short-range optical communication systems.......The research work described in this thesis is devoted to experimental investigation of techniques for cost-effective high-speed optical communications supporting both wired and wireless services. The main contributions of this thesis have expanded the state-of-the-art in two main areas: high...

  2. Outdoor W-Band Hybrid Photonic Wireless Link Based on an Optical SFP+ Module

    DEFF Research Database (Denmark)

    Rommel, Simon; Rodríguez Páez, Juan Sebastián; Chorchos, Łukasz

    2016-01-01

    This letter proposes aW-band hybrid photonic wireless link based on a commercial SFP+ module and experimentally demonstrates its performance. Using a free running laser as local oscillator and heterodyne photonic upconversion, good frequency stability is achieved. Outdoor wireless transmission over...... 225m with a BER below 10-6 is demonstrated and the maximum reach of the system with typical RF components is calculated, finding wireless distances above 2km to be feasible. Being based on a commercial SFP+ the proposed hybrid photonic wireless link offers seamless integration with existing...

  3. OPTICAL WIRELESS COMMUNICATION SYSTEM

    Directory of Open Access Journals (Sweden)

    JOSHUA L.Y. CHIENG

    2016-02-01

    Full Text Available The growing demand of bandwidth in this modern internet age has been testing the existing telecommunication infrastructures around the world. With broadband speeds moving towards the region of Gbps and Tbps, many researches have begun on the development of using optical wireless technology as feasible and future methods to the current wireless technology. Unlike the existing radio frequency wireless applications, optical wireless uses electromagnetic spectrums that are unlicensed and free. With that, this project aim to understand and gain better understanding of optical wireless communication system by building an experimental and simulated model. The quality of service and system performance will be investigated and reviewed. This project employs laser diode as the propagation medium and successfully transferred audio signals as far as 15 meters. On its quality of service, results of the project model reveal that the bit error rate increases, signal-to-noise ratio and quality factor decreases as the link distance between the transmitter and receiver increases. OptiSystem was used to build the simulated model and MATLAB was used to assist signal-to-noise ratio calculations. By comparing the simulated and experimental receiver’s power output, the experimental model’s efficiency is at 66.3%. Other than the system’s performance, challenges and factors affecting the system have been investigated and discussed. Such challenges include beam divergence, misalignment and particle absorption.

  4. Radio-frequency transparent demodulation for broadband hybrid wireless-optical links

    DEFF Research Database (Denmark)

    Zibar, Darko; Sambaraju, Rakesh; Alemany, Ruben

    2010-01-01

    A novel demodulation technique which is transparent to radio-frequency (RF) carrier frequency is presented and experimentally demonstrated for multigigabit wireless signals. The presented demodulation technique employs optical single-sideband filtering, coherent detection, and baseband digital si...

  5. High-Capacity Hybrid Optical Fiber-Wireless Communications Links in Access Networks

    DEFF Research Database (Denmark)

    Pang, Xiaodan

    techniques with both coherent and incoherent optical sources are studied and demonstrated. Employments of advanced modulation formats including phase-shift keying (PSK), M-quadrature amplitude modulation (QAM) and orthogonal frequency-division multiplexing (OFDM) for high speed photonic-wireless transmission...... techniques. In conclusion, the results presented in the thesis show the feasibility of employing mm-wave signals, advanced modulation formats and spatial multiplexing technologies in next generation high capacity hybrid optical fiber-wireless access systems....

  6. SIMO optical wireless links with nonzero boresight pointing errors over M modeled turbulence channels

    Science.gov (United States)

    Varotsos, G. K.; Nistazakis, H. E.; Petkovic, M. I.; Djordjevic, G. T.; Tombras, G. S.

    2017-11-01

    Over the last years terrestrial free-space optical (FSO) communication systems have demonstrated an increasing scientific and commercial interest in response to the growing demands for ultra high bandwidth, cost-effective and secure wireless data transmissions. However, due the signal propagation through the atmosphere, the performance of such links depends strongly on the atmospheric conditions such as weather phenomena and turbulence effect. Additionally, their operation is affected significantly by the pointing errors effect which is caused by the misalignment of the optical beam between the transmitter and the receiver. In order to address this significant performance degradation, several statistical models have been proposed, while particular attention has been also given to diversity methods. Here, the turbulence-induced fading of the received optical signal irradiance is studied through the M (alaga) distribution, which is an accurate model suitable for weak to strong turbulence conditions and unifies most of the well-known, previously emerged models. Thus, taking into account the atmospheric turbulence conditions along with the pointing errors effect with nonzero boresight and the modulation technique that is used, we derive mathematical expressions for the estimation of the average bit error rate performance for SIMO FSO links. Finally, proper numerical results are given to verify our derived expressions and Monte Carlo simulations are also provided to further validate the accuracy of the analysis proposed and the obtained mathematical expressions.

  7. Design and Evaluation of 10-Gbps Inter-satellite Optical Wireless Communication Link for Improved Performance

    Science.gov (United States)

    Gupta, Amit; Nagpal, Shaina

    2017-05-01

    Inter-satellite optical wireless communication (IsOWC) systems can be chosen over existing microwave satellite systems for deploying in space in the future due to their high bandwidth, small size, light weight, low power and low cost. However, the IsOWC system suffers from various attenuations due to weather conditions, turbulence or scintillations which limit its performance and decreases its availability. So, in order to improve the performance, IsOWC system using directly modulated laser source is proposed in this work. The system is designed and evaluated to be suitable for high data rate transmissions up to 10 Gbps. The performance of the system is investigated in order to reduce the cost and complexity of link and improving the quality of information signal. Further the proposed IsOWC system is analysed using BER analyser, power meter and oscilloscope Visualizer.

  8. Space and time diversity in indoor wireless optical links achieving higher data rate

    Science.gov (United States)

    Alqudah, Yazan A.

    2013-02-01

    Multispot diffusing configuration (MSDC) in optical wireless links provide uniform optical power needed for multiaccess and spatial dependence that can be used to allow space diversity techniques over the link. The spatial channels are furnished in MSDC through utilizing multibeam transmitter that produces spatially confined diffusing spots, and a multibranch receiver with small enough branch field-of-view (FOV) to restrict the number of diffusing spots within its FOV. Here, we study different encoding techniques that use space and time diversity to reduce the bit error rate. An improved technique, constellation rotation, is proposed for pulse amplitude modulated (PAM) to increase the Euclidian distance between signal points, and thus reduce bit error. Our study shows that when a cap is placed on the amount of power allocated per channel, the performance of the improved 4-PAM using three spatial channels and soft binary decision provide the optimal performance. When the power allocated per user is restricted, the best performance is obtained through soft binary decision and by using symbols identified by their level and spatial channel to carry 2 bits per signal level-channel.

  9. High capacity hybrid optical fiber-wireless links in 75–300GHz band

    DEFF Research Database (Denmark)

    Cavalcante, Lucas Costa Pereira; Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

    2014-01-01

    Seamless convergence of fiber-optic and the wireless networks is of great interest for enabling transparent delivery of broadband services to users in different locations, including both metropolitan and rural areas. Current demand of bandwidth by end-users, especially using mobile devices, is se...

  10. Underwater optical wireless communication network

    Science.gov (United States)

    Arnon, Shlomi

    2010-01-01

    The growing need for underwater observation and subsea monitoring systems has stimulated considerable interest in advancing the enabling technologies of underwater wireless communication and underwater sensor networks. This communication technology is expected to play an important role in investigating climate change, in monitoring biological, biogeochemical, evolutionary, and ecological changes in the sea, ocean, and lake environments, and in helping to control and maintain oil production facilities and harbors using unmanned underwater vehicles (UUVs), submarines, ships, buoys, and divers. However, the present technology of underwater acoustic communication cannot provide the high data rate required to investigate and monitor these environments and facilities. Optical wireless communication has been proposed as the best alternative to meet this challenge. Models are presented for three kinds of optical wireless communication links: (a) a line-of-sight link, (b) a modulating retroreflector link, and (c) a reflective link, all of which can provide the required data rate. We analyze the link performance based on these models. From the analysis, it is clear that as the water absorption increases, the communication performance decreases dramatically for the three link types. However, by using the scattered light it was possible to mitigate this decrease in some cases. It is concluded from the analysis that a high-data-rate underwater optical wireless network is a feasible solution for emerging applications such as UUV-to-UUV links and networks of sensors, and extended ranges in these applications could be achieved by applying a multi-hop concept.

  11. White LED-based optical wireless link with improved transmission capacity using nonorthogonal multiamplitude phase frequency modulation

    Science.gov (United States)

    Won, Yong-Yuk; Yoon, Sang Min; Seo, Dongsun

    2017-06-01

    A nonorthogonal amplitude, phase, and frequency modulation (APFM) technique that can increase the transmission capacity of an optical wireless link based on white light-emitting diode (LED) is proposed. It is implemented by the simultaneous use of nonorthogonal frequency shift keying (FSK) and quadrature amplitude modulation (QAM). A white LED-based wireless link using a 64-APFM scheme is constructed to experimentally verify the proposed technique, where the 64-APFM scheme is implemented by the combination of nonorthogonal 4-FSK and 16-QAM. Two more bits per symbol are transmitted using the proposed scheme with the same bandwidth of QAM. No intercarrier interference effect is observed at the 0.02-% frequency spacing (0.001 MHz) for the used RF carrier (5 MHz) because the correlation between the received 64-APFM signal and only one carrier at a time is accomplished with the help of digital signal processing. 6-Mbit/s (1-Msymbol/s) data are successfully transmitted through an optical wireless channel with a limited bandwidth of 1 MHz. This indicates that six bits per symbol can be transmitted using the proposed APFM technique at the same physical bandwidth as 16-QAM.

  12. Optical and wireless technologies

    CERN Document Server

    Tiwari, Manish; Singh, Ghanshyam; Minzioni, Paolo

    2018-01-01

    This book presents selected papers from 1st International Conference on Optical and Wireless Technologies, providing insights into the analytical, experimental, and developmental aspects of systems, techniques, and devices in these spheres. It explores the combined use of various optical and wireless technologies in next-generation networking applications, and discusses the latest developments in applications such as photonics, high-speed communication systems and networks, visible light communication, nanophotonics, and wireless and multiple-input-multiple-output (MIMO) systems. The book will serve as a valuable reference resource for academics and researchers across the globe.

  13. Wireless optical transceiver design, link analisys and alignment control for mobile communication

    Science.gov (United States)

    Zhou, Dayong

    Pointing, acquisition and tracking of a free-space optical node in a mobile network experiencing misalignment due to adverse factors including vibration, motion and atmospheric turbulence requires a different approach than traditional free-space optical transceivers. A recent fiber-bundle approach for beam steering at the transmitter was investigated to provide continuous beam coverage at the receiver without the application of mechanical devices. Utilizing multiple fibers-lenses sets at the receiver was also proposed to enhance the tolerance of optical link misalignment. In this work, both laboratory experiments and software simulation were implemented to evaluate the optical link performance for different fiber-bundle-based transceiver setups as the link parameters were varied. The performance was evaluated in terms of the coverage area at the receiver, which is a measure of misalignment tolerance and is dependent not only on wavelength but on other key parameters such as link length, transmitted power, the pattern of transmitters, beam divergence, and the receiver construction. The results showed that fiber-bindle-based transceivers reveal significant potential to maximize the up time of the link, and the results also provide guidance on the further development of the overall system. To incorporate the proposed transceiver designs, an alignment control system was developed and evaluated as well. The laboratory results show that the optical control system successfully recovered and maintained the link while the receiver was in motion and the signal coverage at the target area was enhanced significantly.

  14. Wireless optical telecommunications

    CERN Document Server

    Bouchet, Olivier

    2013-01-01

    Wireless optical communication refers to communication based on the unguided propagation of optical waves. The past 30 years have seen significant improvements in this technique - a wireless communication solution for the current millennium - that offers an alternative to radio systems; a technique that could gain attractiveness due to recent concerns regarding the potential effects of radiofrequency waves on human health.The aim of this book is to look at the free space optics that are already used for the exchange of current information; its many benefits, such as incorporating chan

  15. Single- and Multiband OFDM Photonic Wireless Links in the 75−110 GHz Band Employing Optical Combs

    DEFF Research Database (Denmark)

    Beltrán, M.; Deng, Lei; Pang, Xiaodan

    2012-01-01

    The photonic generation of electrical orthogonal frequency-division multiplexing (OFDM) modulated wireless signals in the 75−110 GHz band is experimentally demonstrated employing in-phase/quadrature electrooptical modulation and optical heterodyn upconversion. The wireless transmission of 16......-quadrature-amplitude-modulation OFDM signals is demonstrated with a bit error rate performance within the forward error correction limits. Signals of 19.1 Gb/s in 6.3-GHz bandwidth are transmitted over up to 1.3-m wireless distance. Optical comb generation is further employed to support different channels...

  16. Bandwidth enhancement of wireless optical communication link using a near-infrared laser over turbid underwater channel

    KAUST Repository

    Lee, It Ee

    2017-11-30

    Underwater wireless optical communication (UWOC) has been widely studied as a promising alternative to establish reliable short-range marine communication links. Microscopic particulates suspended in various ocean, harbor and natural waters will alter the propagation characteristics of the optical signals underwater. In this paper, we demonstrate a gigabit near-infrared (NIR)-based UWOC link using an 808-nm laser diode, to examine the feasibility of the proposed system in mitigating the particle scattering effect over turbid waters. We show that the NIR wavelengths presents greater resilience to the aqueous suspension of these micro-sized particles with a smaller scattering effect due to its longer wavelength, as evident by the smaller variations in the optical beam transmittance. It is also observed that the error performance is improved at higher concentrations albeit the significant reduction in received signal power. We further demonstrate that the overall frequency response of the system exhibits a bandwidth enhancement up to a few tens of MHz with increasing concentrations.

  17. Seamless Optical Fiber-Wireless Millimeter- Wave Transmission Link for Access Networks

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Lebedev, Alexander; Vegas Olmos, Juan José

    2013-01-01

    This paper presents an experimental demonstration of a millimeter-wave wireless bridge in the W-band for transparent broadband fiber access in the sub-urban areas, where full fiber connections are impracticable.......This paper presents an experimental demonstration of a millimeter-wave wireless bridge in the W-band for transparent broadband fiber access in the sub-urban areas, where full fiber connections are impracticable....

  18. Compressive sensing-based channel bandwidth improvement in optical wireless orthogonal frequency division multiplexing link using visible light emitting diode.

    Science.gov (United States)

    Won, Yong-Yuk; Yoon, Sang Min

    2014-08-25

    A new technique, which can compensate for the lack of channel bandwidth in an optical wireless orthogonal frequency division multiplexing (OFDM) link based on a light emitting diode (LED), is proposed. It uses an adaptive sampling and an inverse discrete cosine transform in order to convert an OFDM signal into a sparse waveform so that not only is the important data obtained efficiently but the redundancy one is removed. In compressive sensing (CS), a sparse signal that is sampled below the Nyquist/Shannon limit can be reconstructed successively with enough measurement. This means that the CS technique can increase the data rate of visible light communication (VLC) systems based on LEDs. It is observed that the data rate of the proposed CS-based VLC-OFDM link can be made 1.7 times greater than a conventional VLC-OFDM link (from 30.72 Mb/s to 51.2 Mb/s). We see that the error vector magnitude (EVM) of the quadrature phase shift keying (QPSK) symbol is 31% (FEC limit: EVM of 32%) at a compression ratio of 40%.

  19. Weak beacon detection for air-to-ground optical wireless link establishment.

    Science.gov (United States)

    Han, Yaoqiang; Dang, Anhong; Tang, Junxiong; Guo, Hong

    2010-02-01

    In an air-to-ground free-space optical communication system, strong background interference seriously affects the beacon detection, which makes it difficult to establish the optical link. In this paper, we propose a correlation beacon detection scheme under strong background interference conditions. As opposed to traditional beacon detection schemes, the beacon is modulated by an m-sequence at the transmitting terminal with a digital differential matched filter (DDMF) array introduced at the receiving end to detect the modulated beacon. This scheme is capable of suppressing both strong interference and noise by correlation reception of the received image sequence. In addition, the DDMF array enables each pixel of the image sensor to have its own DDMF of the same structure to process its received image sequence in parallel, thus it makes fast beacon detection possible. Theoretical analysis and an outdoor experiment have been demonstrated and show that the proposed scheme can realize fast and effective beacon detection under strong background interference conditions. Consequently, the required beacon transmission power can also be reduced dramatically.

  20. Scintillation index and performance analysis of wireless optical links over non-Kolmogorov weak turbulence based on generalized atmospheric spectral model.

    Science.gov (United States)

    Cang, Ji; Liu, Xu

    2011-09-26

    Based on the generalized spectral model for non-Kolmogorov atmospheric turbulence, analytic expressions of the scintillation index (SI) are derived for plane, spherical optical waves and a partially coherent Gaussian beam propagating through non-Kolmogorov turbulence horizontally in the weak fluctuation regime. The new expressions relate the SI to the finite turbulence inner and outer scales, spatial coherence of the source and spectral power-law and then used to analyze the effects of atmospheric condition and link length on the performance of wireless optical communication links. © 2011 Optical Society of America

  1. On the Performance of Optical Wireless Links over Random Foggy Channels

    KAUST Repository

    Esmail, Maged

    2017-02-17

    Fog and dust are used to be considered as major performance degrading factors for free space optic (FSO) communication links. Despite the number of field measurements, performed in foggy environments during the last decades, most of the proposed channel attenuation models are deterministic, i.e., assumed the channel attenuation constant over time. Stochastic behavior of the channel is still understudied. In this work, we investigate the probabilistic behavior of the FSO channel in fog and develop a new statistical model for the signal attenuation. Moreover, we derive a probability distribution function (PDF) for the channel state. Using this PDF, we study the FSO system performance considering various metrics including average signal-to-noise ratio, average bit error rate, channel capacity, and probability of outage. Closed form expressions are derived for the average SNR and outage probability. We found acceptable performance with moderate and light fog. However, under thick and dense fog, the system performance poorly deteriorates. Finally, we derived closed form expressions for the average attenuation-distance product and the link availability that will potentially be very helpful for network design and planning.

  2. A Study of Fog Characteristics using Free-Space Optical Wireless Links

    Directory of Open Access Journals (Sweden)

    M. S. Awan

    2010-06-01

    Full Text Available A technique for modeling the fog droplet size distributions using modified gamma distribution has been demonstrated by considering two separate radiation fog events recorded in Graz (Austria and Prague (Czech Republic. The measurement of liquid water content (LWC and the optical attenuations at visible wavelength are used to form equations to obtain the three parameters of the modified gamma distribution i.e., the slope (Λ, the intercept (N0 and the shape parameter (m. Calculated attenuation or LWC from the retrieved parameters are in excellent agreement with attenuation or LWC obtained from the measurement. Hence this method is useful in the study of fog microphysics and in modeling the fog attenuations for terrestrial FSO links in situations when our measurement data contains values of attenuations only, or liquid water content only or both at a particular location. For the two case studies, Graz and Prague, we obtained the DSD parameters Λ=3.547 ± 1.935, N0 =3.834 ± 2.239, m=6.135 ± 2.692 and Λ=5.882 ± 2.889, N0 =13.41 ± 3.875, m=5.288 ± 3.113, respectively. It is evident that the observed behavior of computed modified gamma distribution parameters for Graz and Prague is closely the same and is consistent with the previous literature for the radiation (continental fog. Moreover, we observed the variation of the computed DSD parameters at the different stages of fog (formation, maturity and dissipation phases indicating different microphysical processes at each stage.

  3. Optical Wireless Communications and Autonomous Beam Control Moving User Terminal

    OpenAIRE

    TANGTRONGBENCHASIL, Charoen; HAMADA, Yoichi; KATO, Toshihiro; NONAKA, Koji

    2007-01-01

    Optical wireless communications is a research topic of extreme interest since it offers high data rate (Gbps data rate), security, and RF interference immunity. However, optical wireless communications places severe restrictions on the communications paths; they must be direct beam connections. To increase the number of users and link robustness, optical wireless communications must be able to operate even when obstacles are placed between transmitters and receivers, so optical micro-cell (OM...

  4. An underwater optical wireless communication network

    Science.gov (United States)

    Arnon, Shlomi

    2009-08-01

    The growing need for underwater observation and sub-sea monitoring systems has stimulated considerable interest in advancing the enabling technologies of underwater wireless communication and underwater sensor networks. This communication technology is expected to play an important role in investigating climate change, in monitoring biological, bio-geochemical, evolutionary and ecological changes in the sea, ocean and lake environments and in helping to control and maintain oil production facilities and harbors using unmanned underwater vehicles (UUVs), submarines, ships, buoys, and divers. However, the present technology of underwater acoustic communication cannot provide the high data rate required to investigate and monitor these environments and facilities. Optical wireless communication has been proposed as the best alternative to meet this challenge. We present models of three kinds of optical wireless communication links a) a line-of-sight link, b) a modulating retro-reflector link and c) a reflective link, all of which can provide the required data rate. We analyze the link performance based on these models. From the analysis, it is clear that as the water absorption increases, the communication performance decreases dramatically for the three link types. However, by using the scattered lighted it was possible to mitigate this decrease in some cases. We conclude from the analysis that a high data rate underwater optical wireless network is a feasible solution for emerging applications such as UUV to UUV links and networks of sensors, and extended ranges in these applications could be achieved by applying a multi-hop concept.

  5. Improved analysis of 2.5 Gbps-inter-satellite link (ISL) in inter-satellite optical-wireless communication (IsOWC) system

    Science.gov (United States)

    Sharma, Vishal; Kumar, Naresh

    2013-01-01

    Inter-satellite optical-wireless communication systems (IsOWC), one of the important applications of FSO/WSO technology, will be deployed in space in the near future. The IsOWC systems provide a high bandwidth, small size, light weight, low power and low cost alternative to present microwave satellite systems. In this paper, we have reported the improved investigation through implementation of a square root module using OPTISYSTEM™ simulator to establish an inter-satellite link (ISL) between two satellites estranged by a distance of 1000 Km at data rate of 2.5 Gbps which is not reported in previous investigated work.

  6. Optical wireless connected objects for healthcare.

    Science.gov (United States)

    Toumieux, Pascal; Chevalier, Ludovic; Sahuguède, Stéphanie; Julien-Vergonjanne, Anne

    2015-10-01

    In this Letter the authors explore the communication capabilities of optical wireless technology for a wearable device dedicated to healthcare application. In an indoor environment sensible to electromagnetic perturbations such as a hospital, the use of optical wireless links can permit reducing the amount of radio frequencies in the patient environment. Moreover, this technology presents the advantage to be secure, low-cost and easy to deploy. On the basis of commercially available components, a custom-made wearable device is presented, which allows optical wireless transmission of accelerometer data in the context of physical activity supervision of post-stroke patients in hospital. Considering patient mobility, the experimental performance is established in terms of packet loss as a function of the number of receivers fixed to the ceiling. The results permit to conclude that optical wireless links can be used to perform such mobile remote monitoring applications. Moreover, based on the measurements obtained with one receiver, it is possible to theoretically determine the performance according to the number of receivers to be deployed.

  7. E- and W-band high-capacity hybrid fiber-wireless link

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Pang, Xiaodan; Tafur Monroy, Idelfonso

    2014-01-01

    with transmission over different type of optical fibers and for a number of values for the wireless link distance. Hybrid wireless-optical links can be composed of mature and resilient technology available off-the-shelf, and provide functionalities that can add value to optical access networks, specifically...

  8. 16 Gb/s QPSK Wireless-over-Fibre Link in 75-110GHz Band Employing Optical Heterodyne Generation and Coherent Detection

    DEFF Research Database (Denmark)

    Zibar, Darko; Sambaraju, Rakesh; Caballero Jambrina, Antonio

    2010-01-01

    We report on the first demonstration of QPSK based Wireless-over-Fibre link in 75-110GHz band with a record capacity of up to 16Gb/s. Photonic wireless signal generation by heterodyne beating of free-running lasers and baud-rate digital coherent detection are employed....

  9. 100-GHz Wireless-Over-Fiber Links With Up to 16-Gb/s QPSK Modulation Using Optical Heterodyne Generation and Digital Coherent Detection

    DEFF Research Database (Denmark)

    Sambaraju, R.; Zibar, Darko; Caballero Jambrina, Antonio

    2010-01-01

    In this letter, a novel technique for direct conversion of an optical baseband quadrature phase-shift keying (QPSK) signal to a millimeter-wave wireless signal and subsequent signal demodulation is reported. Optical heterodyne mixing of the optical baseband QPSK signal with a free-running unmodul...

  10. Feasibility of retroreflective transdermal optical wireless communication.

    Science.gov (United States)

    Gil, Yotam; Rotter, Nadav; Arnon, Shlomi

    2012-06-20

    There is an increasing demand for transdermal high-data-rate communication for use with in-body devices, such as pacemakers, smart prostheses, neural signals processors at the brain interface, and cameras acting as artificial eyes as well as for collecting signals generated within the human body. Prominent requirements of these communication systems include (1) wireless modality, (2) noise immunity and (3) ultra-low-power consumption for the in-body device. Today, the common wireless methods for transdermal communication are based on communication at radio frequencies, electrical induction, or acoustic waves. In this paper, we will explore another alternative to these methods--optical wireless communication (OWC)--for which modulated light carries the information. The main advantages of OWC in transdermal communication, by comparison to the other methods, are the high data rates and immunity to external interference availed, which combine to make it a promising technology for next-generation systems. In this paper, we present a mathematical model and experimental results of measurements from direct link and retroreflection link configurations with Gallus gallus domesticus derma as the transdermal channel. The main conclusion from this work is that an OWC link is an attractive communication solution in medical applications. For a modulating retroreflective link to become a competitive solution in comparison with a direct link, low-energy-consumption modulating retroreflectors should be developed.

  11. Impact of wireless link quality across communication layers

    OpenAIRE

    Zhou, J.

    2010-01-01

    Nowadays, wireless networks are used in most of the applications with radio technologies being used in all kinds of wireless networks. In all wireless links, the transmitted packets can be lost. How to identify the quality of a certain wireless link and achieve the best delivery performance over a certain wireless network is an open issue. In this thesis, the performance of wireless mesh network, wireless sensor network and cellular network have been investigated by the method of measurements...

  12. Fully Photonic Wireless Link for Transmission of Synchronization Signals

    Directory of Open Access Journals (Sweden)

    O. Wilfert

    2016-04-01

    Full Text Available Rapid industrialization and increasing demand of business tools for high-speed communications supports the request for optical communications in free space. Copper cables and related technologies such as cable modems and Digital Subscriber Line (DSL are common in existing networks, but do not meet the bandwidth requirement in the future, which opens the door to optical wireless communication technologies. Research in links for optical wireless communication (Infra Red Line of Sight, IR LOS working in the atmosphere is due to the wide support of its development on the world market. Optical wireless communications research is currently focused on increasing the transmission quality of data links. A promising new trend in data connection through IR LOS includes the transfer of accurate time synchronization pulses (time transmission. The article presents problems of modeling and design of a transmitter and receiver with a fully photonic concept. The analysis of the power levels at the link and drawn a model for determining the connection losses at the receiver caused by optical coupling between a Schmidt-Cassegrain telescope and the receiving optical fiber is shown.

  13. Optical wireless communications an emerging technology

    CERN Document Server

    Capsoni, Carlo; Ghassemlooy, Zabih; Boucouvalas, Anthony; Udvary, Eszter

    2016-01-01

    This book focuses on optical wireless communications (OWC), an emerging technology with huge potential for the provision of pervasive and reliable next-generation communications networks. It shows how the development of novel and efficient wireless technologies can contribute to a range of transmission links essential for the heterogeneous networks of the future to support various communications services and traffic patterns with ever-increasing demands for higher data-transfer rates. The book starts with a chapter reviewing the OWC field, which explains different sub-technologies (visible-light, ultraviolet (UV) and infrared (IR) communications) and introduces the spectrum of application areas (indoor, vehicular, terrestrial, underwater, intersatellite, deep space, etc.). This provides readers with the necessary background information to understand the specialist material in the main body of the book, which is in four parts. The first of these deals with propagation modelling and channel characterization of ...

  14. Ultrafast all-optical technologies for bidirectional optical wireless communications.

    Science.gov (United States)

    Jin, Xian; Hristovski, Blago A; Collier, Christopher M; Geoffroy-Gagnon, Simon; Born, Brandon; Holzman, Jonathan F

    2015-04-01

    In this Letter, a spherical retro-modulator architecture is introduced for operation as a bidirectional transceiver in passive optical wireless communication links. The architecture uses spherical retroreflection to enable retroreflection with broad directionality (2π steradians), and it uses all-optical beam interaction to enable modulation on ultrafast timescales (120 fs duration). The spherical retro-modulator is investigated from a theoretical standpoint and is fabricated for testing with three glasses, N-BK7, N-LASF9, and S-LAH79. It is found that the S-LAH79 structure provides the optimal refraction and nonlinearity for the desired retroreflection and modulation capabilities.

  15. Impact of wireless link quality across communication layers

    NARCIS (Netherlands)

    Zhou, J.

    2010-01-01

    Nowadays, wireless networks are used in most of the applications with radio technologies being used in all kinds of wireless networks. In all wireless links, the transmitted packets can be lost. How to identify the quality of a certain wireless link and achieve the best delivery performance over a

  16. Radial transfer of tracking data with wireless links

    CERN Document Server

    Pelikan, Daniel; Brenner, Richard; Dancila, Dragos; Gustafsson, Leif

    2014-01-01

    Wireless data transfer has revolutionized the consumer mar ket for the last decade giving products equipped with transmitters and receiver for wireless data t ransfer. Wireless technology has fea- tures attractive for data transfer in future tracking detec tors. The removal of wires and connectors for data links is certainly beneficial both for the material b udget and the reliability of the system. One other advantage is the freedom of routing signals which t oday is particularly complicated when bringing the data the first 50 cm outside the tracker. Wit h wireless links intelligence can be built into a tracker by introducing communication betwee n tracking layers within a Region Of Interest which would allow the construction of track primit ives in real time. The wireless signal is transmitted by a passive antenna structure which is a radiat ion hard and much less complex object than an optical link. Due to the requirement of high data rate s in detectors a high bandwidth is required. The frequency band aro...

  17. Optical Coherent Receiver Enables THz Wireless Bridge

    DEFF Research Database (Denmark)

    Yu, Xianbin; Liu, Kexin; Zhang, Hangkai

    2016-01-01

    We experimentally demonstrated a 45 Gbit/s 400 GHz photonic wireless communication system enabled by an optical coherent receiver, which has a high potential in fast recovery of high data rate connections, for example, in disaster....

  18. A Millimeter-Wave Digital Link for Wireless MRI.

    Science.gov (United States)

    Aggarwal, Kamal; Joshi, Kiran R; Rajavi, Yashar; Taghivand, Mazhareddin; Pauly, John M; Poon, Ada S Y; Scott, Greig

    2017-02-01

    A millimeter (mm) wave radio is presented in this work to support wireless MRI data transmission. High path loss and availability of wide bandwidth make mm-waves an ideal candidate for short range, high data rata communication required for wireless MRI. The proposed system uses a custom designed integrated chip (IC) mm-wave radio with 60 GHz as radio frequency carrier. In this work, we assess performance in a 1.5 T MRI field, with the addition of optical links between the console room and magnet. The system uses ON-OFF keying (OOK) modulation for data transmission and supports data rates from 200 Mb/s to 2.5 Gb/s for distances up-to 65 cm. The presence of highly directional, linearly polarized, on-chip dipole antennas on the mm-wave radio along with the time division multiplexing (TDM) circuitry allows multiple wireless links to be created simultaneously with minimal inter-channel interference. This leads to a highly scalable solution for wireless MRI.

  19. Underwater Optical Wireless Communications, Networking, and Localization: A Survey

    KAUST Repository

    Saeed, Nasir

    2018-02-28

    Underwater wireless communications can be carried out through acoustic, radio frequency (RF), and optical waves. Compared to its bandwidth limited acoustic and RF counterparts, underwater optical wireless communications (UOWCs) can support higher data rates at low latency levels. However, severe aquatic channel conditions (e.g., absorption, scattering, turbulence, etc.) pose great challenges for UOWCs and significantly reduce the attainable communication ranges, which necessitates efficient networking and localization solutions. Therefore, we provide a comprehensive survey on the challenges, advances, and prospects of underwater optical wireless networks (UOWNs) from a layer by layer perspective which includes: 1) Potential network architectures; 2) Physical layer issues including propagation characteristics, channel modeling, and modulation techniques 3) Data link layer problems covering link configurations, link budgets, performance metrics, and multiple access schemes; 4) Network layer topics containing relaying techniques and potential routing algorithms; 5) Transport layer subjects such as connectivity, reliability, flow and congestion control; 6) Application layer goals and state-of-the-art UOWN applications, and 7) Localization and its impacts on UOWN layers. Finally, we outline the open research challenges and point out the future directions for underwater optical wireless communications, networking, and localization research.

  20. 38.2-Gb/s Optical-Wireless Transmission in 75-110 GHz Based on Electrical OFDM with Optical Comb Expansion

    DEFF Research Database (Denmark)

    Deng, Lei; Pang, Xiaodan; Beltrán, Marta

    2012-01-01

    We demonstrate scalable optical comb- and heterodyning-based generation, optical and 1.3-m wireless transmission, and electrical heterodyne detection of multiband OFDM up to 38.2 Gb/s occupying 14.4-GHz RF bandwidth, for high-capacity optical-wireless links in 75-110 GHz.......We demonstrate scalable optical comb- and heterodyning-based generation, optical and 1.3-m wireless transmission, and electrical heterodyne detection of multiband OFDM up to 38.2 Gb/s occupying 14.4-GHz RF bandwidth, for high-capacity optical-wireless links in 75-110 GHz....

  1. Microwave Photonics Techniques Supporting Flexible Wireless Communications Links

    DEFF Research Database (Denmark)

    Rommel, Simon; Cavalcante, Lucas Costa Pereira; Vegas Olmos, Juan José

    constrains. Microwave photonic techniques support a number of key functionalities required to satisfy above-mentioned demands. We will review, in particular, experimental realizations of a number of functionalities such as mmw generation, detection, optical fiber transport and multi-Gigabit data transmission......Wireless data communication links supporting the next generation 5G and beyond mobile networking face a set of engineering challenges related to the mandatory operation at mmw and higher frequency bands, provide capacities above 10 Gb/s, satisfy latency, robustness, flexibility and low complexity...

  2. Toward multi-Gbps indoor optical wireless multicasting system employing passive diffractive optics.

    Science.gov (United States)

    Oh, C W; Huijskens, F M; Cao, Z; Tangdiongga, E; Koonen, A M J

    2014-05-01

    This Letter presents the evaluation and demonstration of an optical free-space (FS) multicasting system for multi-Gigabits-per-second (multi-Gbps) indoor transmission. These simultaneous line-of-sight links are formed by infrared beams and are beam-steered using a passive diffraction grating. The experiment has resulted in error-free links (bit error rate optical wireless communication and can be seamlessly integrated in in-building fiber networks.

  3. Near-Infrared Wireless Optical Communication with Particulates In-Suspension over the Underwater Channel

    KAUST Repository

    Lee, It Ee

    2017-05-08

    We demonstrate a gigabit near-infrared-based underwater wireless optical communication link using an 808-nm laser diode to mitigate the particle scattering effect in turbid medium. An improvement in the error performance is observed with increasing concentrations.

  4. Indoor Mobile Optical Wireless Antennas for Portable Devices

    Science.gov (United States)

    Challa, Syam Sundar

    A high demand for increasing need for bandwidth and data rates has paved way for optical fiber and optical wireless communications into last mile solutions for optical communications. This dissertation focuses on providing a solution to obtain Optical Wireless (OW) for indoor mobile portable devices. A new optical antenna model is proposed for such portable devices. Optical sweeping in 3D using Acousto Optics Cell Arrays (AOCAs) is proposed. This Opto-electronic method provides better coverage area for Line Of Sight optical link establishment and reconnection. The proposed method also has superior and precise beam divergence manipulation capabilities. Its geometry, coverage area and mobility are analyzed. Indoor dimensions of Height (5m), Width (20m), and Length (20m) are considered. The optical antenna can sweep through the hemispherical shape in the direction of optical beam focal plane using AOCAs. The link budget analysis is done using commercially available component ratings and the optical power for the entire coverage area of the optical antenna is found to be higher than the receiver's minimum sensitivity. The limitations on the nodes such as size and power consumption are studied and the model is designed to run efficiently on power ratings of the portable device battery. The proposed optical antenna can be fabricated in the form of a cube of size 2x2x2 mm. The optical power usage at any given time ranges from 50 mW to 0.5W. The bit error rates from SNR calculations are found to be around 10-10 at data rates of up to 4 Gbps. The Line of Sight (LOS) connection time and reestablishment time ranges from 4 to 7 mus depending on the AOCA process time. VCSEL transceiver optical characteristics are simulated to verify the validity of the model.

  5. Wireless optics protection of fiber via SONET ring closure

    Science.gov (United States)

    Mullen, Ruth Ann; Celmer, Ken T.; Foster, Michael; Wooten, Jimmie; Miller, Jared; Kean, John C.; Carter, Doug; Kefauver, Michael; Singh, Bhupendra; Achour, Maha; Willebrand, Heinz A.

    2001-02-01

    12 A free-space laser link closes an otherwise all-fiber SONET ring, demonstrating for the first time the feasibility of using wireless optics as a back-up to fiber in an application demanding the highest levels of statistical availability and sub-50-ms protection-restoral times. This experiment demonstrates that protocol-transparent wireless optical links can be readily internetworked with industry- standard fiber-based protection protocols to achieve SONET restoral times in the event of a fiber cut. By using the wireless optics as a back-up to fiber rather than as the primary link, end-users are normally protected from the unavoidable burst errors and outages that can arise on a wireless optical link in the event of anomalously poor atmospheric visibility or unanticipated line-of-sight obstructions. While an all-fiber SONET ring operating over physically diverse paths is generally preferred, hybrid fiber/air rings operating over physically-diverse paths (fiber as one path and air as the other) will easily meet or exceed existing Bellcore availability standards for SONET rings. The hybrid part-fiber, part-air ring advantageously protects customers from fiber cuts (a.k.a. `backhoe fade') and may be preferable to over service via either an unprotected fiber spur or over a `collapsed' fiber ring made up of fiber segments sharing a common conduit. The experiment is performed at an OC-12 (622 Mbps) data rate in a point-to-consecutive point configuration which demonstrates the use of a relay site to work-around a line- of-sight obstruction.

  6. Load balancing in integrated optical wireless networks

    DEFF Research Database (Denmark)

    Yan, Ying; Dittmann, Lars; Wong, S-W.

    2010-01-01

    In this paper, we tackle the load balancing problem in Integrated Optical Wireless Networks, where cell breathing technique is used to solve congestion by changing the coverage area of a fully loaded cell tower. Our objective is to design a load balancing mechanism which works closely with the in...

  7. Feedback Control of a Hovercraft over a Wireless Link

    Science.gov (United States)

    2006-01-01

    ABSTRACT Title of thesis : FEEDBACK CONTROL OF A HOVERCRAFT OVER A WIRELESS LINK Zachary Kulis, Master of Science, 2006 Dissertation directed by...to agree nicely. FEEDBACK CONTROL OF A HOVERCRAFT OVER A WIRELESS LINK by Zachary Kulis Thesis submitted to the Faculty of the Graduate School of the...stable position and heading tracking control law for a surface vessel. In this thesis , we explore nonlinear control of a hovercraft over a Bluetooth

  8. Radio link quality estimation in low-power wireless networks

    CERN Document Server

    2013-01-01

    This book provides a comprehensive survey on related work for radio link quality estimation, which covers the characteristics of low-power links, the fundamental concepts of link quality estimation in wireless sensor networks, a taxonomy of existing link quality estimators and their performance analysis. It then shows how link quality estimation can be used for designing protocols and mechanisms such as routing and hand-off. The final part is dedicated to radio interference estimation, generation and mitigation.

  9. Evaluation of coherence interference in optical wireless communication through multiscattering channels.

    Science.gov (United States)

    Kedar, Debbie; Arnon, Shlomi

    2006-05-10

    Optical wireless communication has been the subject of much research in recent years because of the increasing interest in laser satellite-ground links and urban optical wireless communication. The major sources of performance degradation have been identified as the spatial, angular, and temporal spread of the propagating beam when the propagation channel is multiscattering, resulting in reduced power reception and intersignal interference, as well as turbulence-induced scintillations and noise due to receiver circuitry and background illumination. However, coherence effects due to multipath interference caused by a scattering propagation channel do not appear to have been treated in detail in the scientific literature. We attempt a theoretical analysis of coherence interference in optical wireless communication through scattering channels and try to quantify the resultant performance degradation for different media. We conclude that coherence interference is discernible in optical wireless communication through scattering channels and is highly dependent on the microscopic nature of the propagation medium.

  10. TULIP: A Link-Level Protocol for Improving TCP over Wireless Links

    National Research Council Canada - National Science Library

    Parsa, Christina; Garcia-Luna-Aceves, J. J

    1999-01-01

    We present the transport unaware link improvement protocol (TULIP), which dramatically improves the performance of TCP over lossy wireless links, without competing with or modifying the transport- or network-layer protocols...

  11. Flip-chip integrated optical wireless transceivers

    Science.gov (United States)

    O'Brien, Dominic C.; Faulkner, Grahame E.; Zyambo, Emmanuel B.; Edwards, David J.; Stavrinou, Paul N.; Parry, Gareth; Bellon, Jacques; Sibley, Martin J. N.; Lalithambika, Vinod A.; Joyner, Valencia M.; Samsudin, Rina J.; Holburn, David M.; Mears, Robert J.

    2002-12-01

    The widespread use of Optical LANs is dependent on the ability to fabricate low cost transceiver components. These are usually complex, and fabrication involves the integration of optoelectronic and electronic devices, as well as optical components. A consortium of four UK universities are currently involved in a project to demonstrate integrated optical wireless transceiver subsystems that can provide eye-safe line of sight in-building communication at 155Mbit/s and above. In this paper we discuss the flip-chip integration of two-dimensional arrays of novel microcavity LEDs with custom CMOS integrated circuits in order to produce solid state tracking emitters. Design, fabrication and integration of these structures are detailed. The scaleability and future capability available given further optimisation and development of these systems is also discussed.

  12. FireFly: reconfigurable optical wireless networking data centers

    Science.gov (United States)

    Kavehrad, Mohsen; Deng, Peng; Gupta, H.; Longtin, J.; Das, S. R.; Sekar, V.

    2017-01-01

    We explore a novel, free-space optics based approach for building data center interconnects. Data centers (DCs) are a critical piece of today's networked applications in both private and public sectors. The key factors that have driven this trend are economies of scale, reduced management costs, better utilization of hardware via statistical multiplexing, and the ability to elastically scale applications in response to changing workload patterns. A robust DC network fabric is fundamental to the success of DCs and to ensure that the network does not become a bottleneck for high-performance applications. In this context, DC network design must satisfy several goals: high performance (e.g., high throughput and low latency), low equipment and management cost, robustness to dynamic traffic patterns, incremental expandability to add new servers or racks, and other practical concerns such as cabling complexity, and power and cooling costs. Current DC network architectures do not seem to provide a satisfactory solution, with respect to the above requirements. In particular, traditional static (wired) networks are either overprovisioned or oversubscribed. Recent works have tried to overcome the above limitations by augmenting a static (wired) "core" with some flexible links (RF-wireless or optical). These augmented architectures show promise, but offer only incremental improvement in performance. Specifically, RFwireless based augmented solutions also offer only limited performance improvement, due to inherent interference and range constraints of RF links. This paper explores an alternative design point—a fully flexible and all-wireless DC interrack network based on free-space optical (FSO) links. We call this FireFly as in; Free-space optical Inter-Rack nEtwork with high FLexibilitY. We will present our designs and tests using various configurations that can help the performance and reliability of the FSO links.

  13. Optical wireless communications system and channel modelling with Matlab

    CERN Document Server

    Ghassemlooy, Z

    2012-01-01

    Detailing a systems approach, Optical Wireless Communications: System and Channel Modelling with MATLAB(R), is a self-contained volume that concisely and comprehensively covers the theory and technology of optical wireless communications systems (OWC) in a way that is suitable for undergraduate and graduate-level students, as well as researchers and professional engineers. Incorporating MATLAB(R) throughout, the authors highlight past and current research activities to illustrate optical sources, transmitters, detectors, receivers, and other devices used in optical wireless communications. The

  14. Bidirectional fiber-IVLLC and fiber-wireless convergence system with two orthogonally polarized optical sidebands.

    Science.gov (United States)

    Lu, Hai-Han; Wu, Hsiao-Wen; Li, Chung-Yi; Ho, Chun-Ming; Yang, Zih-Yi; Cheng, Ming-Te; Lu, Chang-Kai

    2017-05-01

    A bidirectional fiber-invisible laser light communication (IVLLC) and fiber-wireless convergence system with two orthogonally polarized optical sidebands for hybrid cable television (CATV)/millimeter-wave (MMW)/baseband (BB) signal transmission is proposed and experimentally demonstrated. Two optical sidebands generated by a 60-GHz MMW signal are orthogonally polarized and separated into different polarizations. These orthogonally polarized optical sidebands are delivered over a 40-km single-mode fiber (SMF) transport to effectually reduce the fiber dispersion induced by a 40-km SMF transmission and the distortion caused by the parallel polarized optical sidebands. To the best of our knowledge, this work is the first to adopt two orthogonally polarized optical sidebands in a bidirectional fiber-IVLLC and fiber-wireless convergence system to reduce fiber dispersion and distortion effectually. Good carrier-to-noise ratio, composite second order, composite triple beat, and bit error rate (BER) are achieved for downlink transmission at a 40-km SMF operation and a 100-m free-space optical (FSO) link/3-m RF wireless transmission. For up-link transmission, good BER performance is acquired over a 40-km SMF transport and a 100-m FSO link. The approach presented in this work signifies the advancements in the convergence of SMF-based backbone and optical/RF wireless-based feeder.

  15. Wireless Energy and Information Transmission in FSO and RF-FSO Links

    KAUST Repository

    Makki, Behrooz

    2017-09-22

    We propose and analyze a wireless energy and information transmission scheme in free-space optical (FSO) links. The results are presented for both quasi-static and fast-fading conditions. We derive closed-form expressions for throughput, outage probability and optimal power allocation optimizing the system throughput/outage probability. Finally, we complement the FSO link with an additional radio frequency (RF) link to create a hybrid RF-FSO system and reduce the system outage probability. The results show that joint implementation of the RF and FSO links leads to considerable performance improvement, compared to the cases with only FSO-based communication.

  16. Wireless communication link for capsule endoscope at 600 MHz.

    Science.gov (United States)

    Khaleghi, A; Balasingham, I

    2015-01-01

    Simulation of a wireless communication link for a capsule endoscopy is presented for monitoring of small intestine in humans. The realized communication link includes the transmitting capsule antenna, the outside body receiving antenna and the model of the human body. The capsule antenna is designed for operating at the frequency band of 600 MHz with an impedance bandwidth of 10 MHz and omnidirectional radiation pattern. The quality of the communication link is improved by using directive antenna outside body inside matching layer for electromagnetic wave tuning to the body. The outside body antenna has circular polarization that guaranteeing the communication link for different orientations of the capsule inside intestine. It is shown that the path loss for the capsule in 60 mm from the abdomen surface varies between 37-47 dB in relation to the antenna orientation. This link can establish high data rate wireless communications for capsule endoscopy.

  17. Underwater optical wireless communications: depth-dependent beam refraction.

    Science.gov (United States)

    Johnson, Laura J; Green, Roger J; Leeson, Mark S

    2014-11-01

    Global refractive gradients in seawater cause pointing problems for optical wireless communications. A refractive index depth profile of the Pacific Ocean was calculated from measured salinity, temperature, and pressure, determining the end points of a refracted and nonrefracted 200 m communication link. Numerical ray tracing was used with a point source for angles between 10° and 80° and transmission wavelengths of 500-650 nm; the maximum end-point difference found was 0.23 m. A 500 nm laser with a 0.57° full-angle FOV was traced; the nonrefracted receiver location was outside the FOV for all links angled >15° to the vertical. However, most pointing issues underwater are unlikely to be significant with suitable FOV choice and natural scattering of the source.

  18. An Accurate Link Correlation Estimator for Improving Wireless Protocol Performance

    Directory of Open Access Journals (Sweden)

    Zhiwei Zhao

    2015-02-01

    Full Text Available Wireless link correlation has shown significant impact on the performance of various sensor network protocols. Many works have been devoted to exploiting link correlation for protocol improvements. However, the effectiveness of these designs heavily relies on the accuracy of link correlation measurement. In this paper, we investigate state-of-the-art link correlation measurement and analyze the limitations of existing works. We then propose a novel lightweight and accurate link correlation estimation (LACE approach based on the reasoning of link correlation formation. LACE combines both long-term and short-term link behaviors for link correlation estimation. We implement LACE as a stand-alone interface in TinyOS and incorporate it into both routing and flooding protocols. Simulation and testbed results show that LACE: (1 achieves more accurate and lightweight link correlation measurements than the state-of-the-art work; and (2 greatly improves the performance of protocols exploiting link correlation.

  19. Integrated resource management for Hybrid Optical Wireless (HOW) networks

    DEFF Research Database (Denmark)

    Yan, Ying; Yu, Hao; Wessing, Henrik

    2009-01-01

    resource sharing scheme and an integrated admission control scheme for the hybrid optical wireless networks. It provides QoS guarantees for connections through both optical and wireless domain. Simulation results show that our proposed scheme improves QoS performances in terms of high throughput and low......Efficient utilization of available bandwidth over hybrid optical wireless networks is a critical issue, especially for multimedia applications with high data rates and stringent Quality of Service (QoS) requirements. In this paper, we propose an integrated resource management including an enhanced...

  20. Capacity Bounds for Parallel Optical Wireless Channels

    KAUST Repository

    Chaaban, Anas

    2016-01-01

    A system consisting of parallel optical wireless channels with a total average intensity constraint is studied. Capacity upper and lower bounds for this system are derived. Under perfect channel-state information at the transmitter (CSIT), the bounds have to be optimized with respect to the power allocation over the parallel channels. The optimization of the lower bound is non-convex, however, the KKT conditions can be used to find a list of possible solutions one of which is optimal. The optimal solution can then be found by an exhaustive search algorithm, which is computationally expensive. To overcome this, we propose low-complexity power allocation algorithms which are nearly optimal. The optimized capacity lower bound nearly coincides with the capacity at high SNR. Without CSIT, our capacity bounds lead to upper and lower bounds on the outage probability. The outage probability bounds meet at high SNR. The system with average and peak intensity constraints is also discussed.

  1. Underwater Wireless Acousto-Optic Waveguide (UWAOW)

    Science.gov (United States)

    Giuliano, Giovanni; Kent, Lionel W. J.; Laycock, Leslie C.

    2017-10-01

    The present study originated in the lack of research into achieving underwater total internal reflection (TIR) via the acousto-optic effect. The uniqueness of this technique exists in the fact that it is based on a high sound pressure level which induces a localised change in refractive index of seawater sufficient to achieve total internal reflection within the communication channel. Different transducer systems for generating the pressure wave have been investigated and take the form of a wave which may be either a standing wave, or a novel beamforming technique. The former is based on an array of transducers and with an acoustic mirror at the receiver in order to establish the standing wave. The alternative approach relies on the high intrinsic directionality of a novel beamformer where an annular transducer array is examined as an acoustic source. In this paper, the main characteristics of the acoustic optic waveguide will be presented. This will include both sound and light propagation in the ocean, TIR, novel beam propagation, the refractive index of water as a function of the externally applied acoustic pressure, and the acoustic technology. The modelled results, the limitations imposed by the challenging medium, and the system requirements required to obtain an Underwater Wireless Acousto-Optic Waveguide (UWAOW) will be also addressed.

  2. LED Based Optical Wireless Communication System for WBAN

    Directory of Open Access Journals (Sweden)

    ATTIYA BAQAI

    2016-10-01

    Full Text Available In this paper the O-WBANs (Optical Wireless Body Area Networks is presented as an alternative to the radio and microwave BANs which are plagued with issues like interference, power hungry, hazardous and costly spectrum. Various experiments performed in this work demonstrate the feasibility of LED (Light-Emitting Diode based optical systems to be used for BANs. The system cost is kept as low as possible. Mainly the effects on the optical link are observed under ambient light and with different modulation schemes by varying link distance and line of sight in this paper. Experimental results reveal the satisfactory link availability up to the distance of 7 feet (around 2m, the optimum range of WBAN and within the field of view of 30-60º. The low cost solution presented in this paper meets the WBANs data rate requirement for physiological data (i.e. 10-100 kbps. As IR (Infra-Red signals do not provide any interference with the signals generated by the medical equipment of hospitals which is the problem in case of RF or microwave signals, additionally the IR signals are confined within a room hence IR signaling can prove to be potential candidate for WBAN fulfilling its security and limited access requirement.

  3. TCP with header checksum option for wireless links: An analytical ...

    Indian Academy of Sciences (India)

    TCP was designed for wired networks, where packet losses are mainly due to congestion. In today's world, more and more people use their mobile devices to access the Internet either for work or entertainment, where TCP runs over wireless links and is subjected to more corruption losses as compared to congestion losses.

  4. Non-line-of-sight underwater optical wireless communication network.

    Science.gov (United States)

    Arnon, Shlomi; Kedar, Debbie

    2009-03-01

    The growing need for ocean observation systems has stimulated considerable interest within the research community in advancing the enabling technologies of underwater wireless communication and underwater sensor networks. Sensors and ad hoc sensor networks are the emerging tools for performing extensive data-gathering operations on land, and solutions in the subsea setting are being sought. Efficient communication from the sensors and within the network is critical, but the underwater environment is extremely challenging. Addressing the special features of underwater wireless communication in sensor networks, we propose a novel non-line-of-sight network concept in which the link is implemented by means of back-reflection of the propagating optic signal at the ocean-air interface and derive a mathematical model of the channel. Point-to-multipoint links can be achieved in an energy efficient manner and broadcast broadband communications, such as video transmissions, can be executed. We show achievable bit error rates as a function of sensor node separation and demonstrate the feasibility of this concept using state-of-the-art silicon photomultiplier detectors.

  5. Link-Quality Measurement and Reporting in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Byoungjo Choi

    2013-03-01

    Full Text Available Wireless Sensor networks (WSNs are created by small hardware devices that possess the necessary functionalities to measure and exchange a variety of environmental data in their deployment setting. In this paper, we discuss the experiments in deploying a testbed as a first step towards creating a fully functional heterogeneous wireless network-based underground monitoring system. The system is mainly composed of mobile and static ZigBee nodes, which are deployed on the underground mine galleries for measuring ambient temperature. In addition, we describe the measured results of link characteristics such as received signal strength, latency and throughput for different scenarios.

  6. A Combined Radio and Underwater Wireless Optical Communication System based on Buoys

    Science.gov (United States)

    Song, Yuhang; Tong, Zheng; Cong, Bo; Yu, Xiangyu; Kong, Meiwei; Lin, Aobo

    2016-02-01

    We propose a system of combining radio and underwater wireless optical communication based on buoys for real-time image and video transmission between underwater vehicles and the base station on the shore. We analysis how the BER performance is affected by the link distance and the deflection angle of the light source using Monte Carlo simulation.

  7. Optical frequency upconversion technique for transmission of wireless MIMO-type signals over optical fiber.

    Science.gov (United States)

    Shaddad, R Q; Mohammad, A B; Al-Gailani, S A; Al-Hetar, A M

    2014-01-01

    The optical fiber is well adapted to pass multiple wireless signals having different carrier frequencies by using radio-over-fiber (ROF) technique. However, multiple wireless signals which have the same carrier frequency cannot propagate over a single optical fiber, such as wireless multi-input multi-output (MIMO) signals feeding multiple antennas in the fiber wireless (FiWi) system. A novel optical frequency upconversion (OFU) technique is proposed to solve this problem. In this paper, the novel OFU approach is used to transmit three wireless MIMO signals over a 20 km standard single mode fiber (SMF). The OFU technique exploits one optical source to produce multiple wavelengths by delivering it to a LiNbO3 external optical modulator. The wireless MIMO signals are then modulated by LiNbO3 optical intensity modulators separately using the generated optical carriers from the OFU process. These modulators use the optical single-sideband with carrier (OSSB+C) modulation scheme to optimize the system performance against the fiber dispersion effect. Each wireless MIMO signal is with a 2.4 GHz or 5 GHz carrier frequency, 1 Gb/s data rate, and 16-quadrature amplitude modulation (QAM). The crosstalk between the wireless MIMO signals is highly suppressed, since each wireless MIMO signal is carried on a specific optical wavelength.

  8. Optical Frequency Upconversion Technique for Transmission of Wireless MIMO-Type Signals over Optical Fiber

    Directory of Open Access Journals (Sweden)

    R. Q. Shaddad

    2014-01-01

    Full Text Available The optical fiber is well adapted to pass multiple wireless signals having different carrier frequencies by using radio-over-fiber (ROF technique. However, multiple wireless signals which have the same carrier frequency cannot propagate over a single optical fiber, such as wireless multi-input multi-output (MIMO signals feeding multiple antennas in the fiber wireless (FiWi system. A novel optical frequency upconversion (OFU technique is proposed to solve this problem. In this paper, the novel OFU approach is used to transmit three wireless MIMO signals over a 20 km standard single mode fiber (SMF. The OFU technique exploits one optical source to produce multiple wavelengths by delivering it to a LiNbO3 external optical modulator. The wireless MIMO signals are then modulated by LiNbO3 optical intensity modulators separately using the generated optical carriers from the OFU process. These modulators use the optical single-sideband with carrier (OSSB+C modulation scheme to optimize the system performance against the fiber dispersion effect. Each wireless MIMO signal is with a 2.4 GHz or 5 GHz carrier frequency, 1 Gb/s data rate, and 16-quadrature amplitude modulation (QAM. The crosstalk between the wireless MIMO signals is highly suppressed, since each wireless MIMO signal is carried on a specific optical wavelength.

  9. Optical Frequency Upconversion Technique for Transmission of Wireless MIMO-Type Signals over Optical Fiber

    Science.gov (United States)

    Shaddad, R. Q.; Mohammad, A. B.; Al-Gailani, S. A.; Al-Hetar, A. M.

    2014-01-01

    The optical fiber is well adapted to pass multiple wireless signals having different carrier frequencies by using radio-over-fiber (ROF) technique. However, multiple wireless signals which have the same carrier frequency cannot propagate over a single optical fiber, such as wireless multi-input multi-output (MIMO) signals feeding multiple antennas in the fiber wireless (FiWi) system. A novel optical frequency upconversion (OFU) technique is proposed to solve this problem. In this paper, the novel OFU approach is used to transmit three wireless MIMO signals over a 20 km standard single mode fiber (SMF). The OFU technique exploits one optical source to produce multiple wavelengths by delivering it to a LiNbO3 external optical modulator. The wireless MIMO signals are then modulated by LiNbO3 optical intensity modulators separately using the generated optical carriers from the OFU process. These modulators use the optical single-sideband with carrier (OSSB+C) modulation scheme to optimize the system performance against the fiber dispersion effect. Each wireless MIMO signal is with a 2.4 GHz or 5 GHz carrier frequency, 1 Gb/s data rate, and 16-quadrature amplitude modulation (QAM). The crosstalk between the wireless MIMO signals is highly suppressed, since each wireless MIMO signal is carried on a specific optical wavelength. PMID:24772009

  10. Affordable underwater wireless optical communication using LEDs

    Science.gov (United States)

    Pilipenko, Vladimir; Arnon, Shlomi

    2013-09-01

    In recent years the need for high data rate underwater wireless communication (WC) has increased. Nowadays, the conventional technology for underwater communication is acoustic. However, the maximum data rate that acoustic technology can provide is a few kilobits per second. On the other hand, emerging applications such as underwater imaging, networks of sensors and swarms of underwater vehicles require much faster data rates. As a result, underwater optical WC, which can provide much higher data rates, has been proposed as an alternative means of communication. In addition to high data rates, affordable communication systems become an important feature in the development requirements. The outcome of these requirements is a new system design based on off-the-shelf components such as blue and green light emitting diodes (LEDs). This is due to the fact that LEDs offer solutions characterized by low cost, high efficiency, reliability and compactness. However, there are some challenges to be met when incorporating LEDs as part of the optical transmitter, such as low modulation rates and non linearity. In this paper, we review the main challenges facing the incorporation of LEDs as an integral part of underwater WC systems and propose some techniques to mitigate the LED limitations in order to achieve high data rate communication

  11. DWDM Fiber-Wireless Access System with Centralized Optical Frequency Comb-based RF Carrier Generation

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Beltrán, Marta; Sánchez, José

    2013-01-01

    We propose and experimentally demonstrate an optical wireless DWDM system at 60 GHz with optical incoherent heterodyne up-conversion using an optical frequency comb. Multiple users with wireline and wireless services are simultaneously supported.......We propose and experimentally demonstrate an optical wireless DWDM system at 60 GHz with optical incoherent heterodyne up-conversion using an optical frequency comb. Multiple users with wireline and wireless services are simultaneously supported....

  12. Design of Optical Wireless Networks with Fair Traffic Flows

    Directory of Open Access Journals (Sweden)

    Artur Tomaszewski

    2014-01-01

    Full Text Available The paper presents a method for optimising the wireless optical network that carries elastic packet traffic. The particular focus is on modelling the effect of elastic traffic flows slowing down in response to the decrease of the optical transmission systems’ capacity at bad weather conditions. A mathematical programming model of the network design problem is presented that assumes that the packet rates of elastic traffic flows decrease fairly. While practically any subset of network links can be simultaneously affected by unfavourable transmission conditions, a particular challenge of solving the problem results from a huge number of network states considered in the model. Therefore, how the problem can be solved by generating the most unfavourable network states is presented. Moreover, it is proved that it is entirely sufficient to consider only the states that correspond to the decrease of capacity on a single link. Finally, as the general problem is nonlinear, it is shown that the problem can be transformed to a linear MIP problem and solved effectively when single-path routing of traffic flows is assumed.

  13. Underwater Optical Wireless Channel Modeling Using Monte-Carlo Method

    Science.gov (United States)

    Saini, P. Sri; Prince, Shanthi

    2011-10-01

    At present, there is a lot of interest in the functioning of the marine environment. Unmanned or Autonomous Underwater Vehicles (UUVs or AUVs) are used in the exploration of the underwater resources, pollution monitoring, disaster prevention etc. Underwater, where radio waves do not propagate, acoustic communication is being used. But, underwater communication is moving towards Optical Communication which has higher bandwidth when compared to Acoustic Communication but has shorter range comparatively. Underwater Optical Wireless Communication (OWC) is mainly affected by the absorption and scattering of the optical signal. In coastal waters, both inherent and apparent optical properties (IOPs and AOPs) are influenced by a wide array of physical, biological and chemical processes leading to optical variability. The scattering effect has two effects: the attenuation of the signal and the Inter-Symbol Interference (ISI) of the signal. However, the Inter-Symbol Interference is ignored in the present paper. Therefore, in order to have an efficient underwater OWC link it is necessary to model the channel efficiently. In this paper, the underwater optical channel is modeled using Monte-Carlo method. The Monte Carlo approach provides the most general and most flexible technique for numerically solving the equations of Radiative transfer. The attenuation co-efficient of the light signal is studied as a function of the absorption (a) and scattering (b) coefficients. It has been observed that for pure sea water and for less chlorophyll conditions blue wavelength is less absorbed whereas for chlorophyll rich environment red wavelength signal is absorbed less comparative to blue and green wavelength.

  14. Self-aligning LED-based optical link

    Science.gov (United States)

    Shen, Thomas C.; Drost, Robert J.; Rzasa, John R.; Sadler, Brian M.; Davis, Christopher C.

    2016-09-01

    The steady advances in light-emitting diode (LED) technology have motivated the use of LEDs in optical wireless communication (OWC) applications such as indoor local area networks (LANs) and communication between mobile platforms (e.g., robots, vehicles). In contrast to traditional radio frequency (RF) wireless communication, OWC utilizes electromagnetic spectrum that is largely unregulated and unrestricted. OWC communication may be especially useful in RF-denied environments, in which RF communication may be prohibited or undesirable. However, OWC does present some challenges, including the need to maintain alignment between potentially moving nodes. We describe a novel system for link alignment that is composed of a hyperboloidal mirror, camera, and gimbal. The experimental system is able to use the mirror and camera to detect an LED beacon of a neighboring node and estimate its bearing (azimuth and elevation), point the gimbal towards the beacon, and establish an optical link.

  15. Steerable pencil beams for multi-Gbps indoor optical wireless communication.

    Science.gov (United States)

    Oh, C W; Tangdiongga, E; Koonen, A M J

    2014-09-15

    We report a novel optical wireless communication (OWC) system solution that supports multi-Gbps (Gigabit-per-second) capacity for indoors. Narrow beams, termed as pencil beams, are directed to wireless users using a tunable laser and a passive diffractive optical element. This enables a wide coverage of ultra-high-capacity communication links to serve multiple network users simultaneously. Experimental results demonstrating data rates of up to 10 Gbps, with on-off keying modulation format, over a distance of more than 2.5 m, are reported. Error-free links beam-steered over a total wavelength range of 130 nm, with steering angle of 17.16°, have been achieved. This system is proposed for short-range OWC and is promising for seamless integration in in-building optical networks.

  16. Procedure to measure real time latency using software defined radio in a W-band fiber-wireless link

    DEFF Research Database (Denmark)

    Rico-Martínez, Mónica; Morales, Alvaro; Mehmeri, Victor

    2017-01-01

    Reducing latency is a major challenge for current telecommunications systems. 5G networks are envisioned to achieve end-to-end latencies below 1 ms, thus enabling the Internet of Things (IoT) evolution and new applications such as Tactile Internet. In this article, we present a new procedure to m...... to measure real time latency in hybrid optical-wireless links. We obtained 2 ms end to end latency using Software Defined Radio to measure latency in a physical setup. We tested the procedure on W-band fiber-wireless link and validated the results against PING over GRE tunnel....

  17. High Data Rate Optical Wireless Communications Based on Ultraviolet Band

    KAUST Repository

    Sun, Xiaobin

    2017-10-01

    Optical wireless communication systems based on ultraviolet (UV)-band has a lot inherent advantages, such as low background solar radiation, low device dark noise. Besides, it also has small restrictive requirements for PAT (pointing, acquisition, and tracking) because of its high atmospheric scattering with molecules and aerosols. And these advantages are driving people to explore and utilize UV band for constructing and implementing a high-data-rate, less PAT communication links, such as diffuse-line-of-sight links (diffuse-LOS) and non-line-of-sight (NLOS). The responsivity of the photodetector at UV range is far lower than that of visible range, high power UV transmitters which can be easily modulated are under investigation. These factors make it is hard to realize a high-data-rate diffuse-LOS or NLOS UV communication links. To achieve a UV link mentioned above with current devices and modulation schemes, this thesis presents some efficient modulation schemes and available devices for the time being. Besides, a demonstration of ultraviolet-B (UVB) communication link is implemented utilizing quadrature amplitude modulation (QAM) orthogonal frequency-division multiplexing (OFDM). The demonstration is based on a 294-nm UVB-light-emitting-diode (UVB-LED) with a full-width at half-maximum (FWHM) of 9 nm, and according to the measured L-I-V curve, we set the bias voltage as 7V for maximum the ac amplitude and thus get a high signal-noise-ratio (SNR) channel, and the light output power is 190 μW with such bias voltage. Besides, there is a unique silica gel lens on top of the LED to concentrate the beam. A -3-dB bandwidth of 29 MHz was measured and a high-speed near-solar-blind communication link with a data rate of 71 Mbit/s was achieved using 8-QAM-OFDM at perfect alignment, and 23.6 Mbit/s using 2-QAM-OFDM when the angle subtended by the pointing direction of the UVB-LED and photodetector (PD) is 12 degrees, thus establishing a diffuse-line-of-sight (LOS) link

  18. Using turbocodes on optical links

    Directory of Open Access Journals (Sweden)

    Glenn Claes

    2006-04-01

    Full Text Available The fast evolving telecommunication world is permanently in search for faster and better communication links. On one hand, turbo codes are like a dream come true. Due to their amazing performance, they have become the reference in the word of error detecting and correcting codes. On the other hand, broadband transmission channels like optical fibres can meet the need for higher transmission velocity. In this paper therefore we will bring these two elements together and thus the performance of turbocodes on optical links will be studied. First the turbocode will be optimised throughout an individual analysis of each of its design parameters. Moreover it wil be shown that turbocodes have much better performance than the well known Reed-Solomon codes. Finally we will show that the 8Bit/10Bit code, which is required to comply with the Gigabit Ethernet standard, becomes superfluous when working with turbocodes. All tests were carried out on multimode graded-index glass fibres.

  19. Review of optical wireless communications for data centers

    Science.gov (United States)

    Arnon, Shlomi

    2017-10-01

    A data center (DC) is a facility either physical or virtual, for running applications, searching, storage, management and dissemination of information known as cloud computing, which consume a huge amount of energy. A DC includes thousands of servers, communication and storage equipment and a support system including an air conditioning system, security, monitoring equipment and electricity regulator units. Data center operators face the challenges of meeting exponentially increasing demands for network bandwidth without unreasonable increases in operation and infrastructure cost. In order to meet the requirements of moderate increase in operation and infrastructure cost technology, a revolution is required. One way to overcome the shortcomings of traditional static (wired) data center architectures is use of a hybrid network based on fiber and optical wireless communication (OWC) or free space optics (FSO). The OWC link could be deployed on top of the existing cable/fiber network layer, so that live migration could be done easily and dynamically. In that case the network topology is flexible and adapts quickly to changes in traffic, heat distribution, power consumption and characteristics of the applications. In addition, OWC could provide an easy way to maintain and scale up data centers. As a result total cost of ownership could be reduced and the return on investment could be increased. In this talk we will review the main OWC technologies applicable for data centers, indicate how energy could be saved using OWC multichannel communication and discuss the issue of OWC pointing accuracy for data center scenario.

  20. Deflating link buffers in a wireless mesh network

    KAUST Repository

    Jamshaid, Kamran

    2014-05-01

    We analyze the problem of buffer sizing for backlogged TCP flows in 802.11-based wireless mesh networks. Our objective is to maintain high network utilization while providing low queueing delays. Unlike wired networks where a single link buffer feeds a bottleneck link, the radio spectral resource in a mesh network is shared among a set of contending mesh routers. We account for this by formulating the buffer size problem as sizing a collective buffer distributed over a set of interfering nodes. In this paper we propose mechanisms for sizing and distributing this collective buffer among the mesh nodes constituting the network bottleneck. Our mechanism factors in the network topology and wireless link rates, improving on pre-set buffer allocations that cannot optimally work across the range of configurations achievable with 802.11 radios. We evaluate our mechanisms using simulations as well as experiments on a testbed. Our results show that we can reduce the RTT of a flow by 6× or more, at the cost of less than 10% drop in end-to-end flow throughput.

  1. Capacity Limit, Link Scheduling and Power Control in Wireless Networks

    Science.gov (United States)

    Zhou, Shan

    2013-01-01

    The rapid advancement of wireless technology has instigated the broad deployment of wireless networks. Different types of networks have been developed, including wireless sensor networks, mobile ad hoc networks, wireless local area networks, and cellular networks. These networks have different structures and applications, and require different…

  2. 100-Gbps hybrid optical fiber-wireless transmission

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Caballero Jambrina, Antonio; Deng, Lei

    2013-01-01

    We present experimental results on using optical transmission technologies such as I&Q modulators, digital coherent receivers, heterodyne up-conversion in fast photodiodes, to generate, transmit and detect high capacity wireless transmission. Both OFDM and QAM modulation formats are tested in the W...

  3. Underwater Wireless Optical Communication System Using Blue LEDs

    Science.gov (United States)

    Lin, Aobo; Tong, Zheng; Song, Yuhang; Kong, Meiwei; Xu, Jing

    2016-02-01

    We demonstrate a self-designed underwater wireless optical communication system using blue LEDs. The performance of the transmitter and receiver was experimentally investigated. Four different square wave signals (10 KHz, 100 KHz, 500 KHz and 1 MHz) were successfully transmitted via a short water channel at the first phase.

  4. An Ultraviolet Optical Wireless Sensor Network in Multi-scattering Channels

    Science.gov (United States)

    Kedar, Debbie; Arnon, Shlomi

    2006-10-01

    Networks of wirelessly communicating sensors are a promising technology for future data-gathering systems in both civilian and military applications including medical and environmental monitoring and surveillance, home security and industry. Optical wireless communication is a potential solution for the links, particularly thanks to the small and lightweight hardware and low power consumption. A noteworthy feature of optical wireless communication at ultraviolet wavelengths is that scattering of radiation by atmospheric particles is significant, so that the backscattering of light by these particles can function as a vehicle of communication as if numerous tiny reflecting mirrors were placed in the atmosphere. Also, almost no solar radiation penetrates the atmosphere in this spectral band, which is hence called the solar blind ultraviolet spectrum, so that very large field-of-view receivers can be used. In this paper we present a model of a non-line-of-sight (NLOS) optical wireless sensor network operating in the solar blind ultraviolet spectrum. The system feasibility is evaluated and found to facilitate miniature operational sensor networks. The problem of multi-access interference is addressed and the possibility of overcoming it using WDM diversity methods is investigated.

  5. Link Investigation of IEEE 802.15.4 Wireless Sensor Networks in Forests.

    Science.gov (United States)

    Ding, Xingjian; Sun, Guodong; Yang, Gaoxiang; Shang, Xinna

    2016-06-27

    Wireless sensor networks are expected to automatically monitor the ecological evolution and wildlife habits in forests. Low-power links (transceivers) are often adopted in wireless sensor network applications, in order to save the precious sensor energy and then achieve long-term, unattended monitoring. Recent research has presented some performance characteristics of such low-power wireless links under laboratory or outdoor scenarios with less obstacles, and they have found that low-power wireless links are unreliable and prone to be affected by the target environment. However, there is still less understanding about how well the low-power wireless link performs in real-world forests and to what extent the complex in-forest surrounding environments affect the link performances. In this paper, we empirically evaluate the low-power links of wireless sensors in three typical different forest environments. Our experiment investigates the performance of the link layer compatible with the IEEE 802.15.4 standard and analyzes the variation patterns of the packet reception ratio (PRR), the received signal strength indicator (RSSI) and the link quality indicator (LQI) under diverse experimental settings. Some observations of this study are inconsistent with or even contradict prior results that are achieved in open fields or relatively clean environments and thus, provide new insights both into effectively evaluating the low-power wireless links and into efficiently deploying wireless sensor network systems in forest environments.

  6. Link Investigation of IEEE 802.15.4 Wireless Sensor Networks in Forests

    Science.gov (United States)

    Ding, Xingjian; Sun, Guodong; Yang, Gaoxiang; Shang, Xinna

    2016-01-01

    Wireless sensor networks are expected to automatically monitor the ecological evolution and wildlife habits in forests. Low-power links (transceivers) are often adopted in wireless sensor network applications, in order to save the precious sensor energy and then achieve long-term, unattended monitoring. Recent research has presented some performance characteristics of such low-power wireless links under laboratory or outdoor scenarios with less obstacles, and they have found that low-power wireless links are unreliable and prone to be affected by the target environment. However, there is still less understanding about how well the low-power wireless link performs in real-world forests and to what extent the complex in-forest surrounding environments affect the link performances. In this paper, we empirically evaluate the low-power links of wireless sensors in three typical different forest environments. Our experiment investigates the performance of the link layer compatible with the IEEE 802.15.4 standard and analyzes the variation patterns of the packet reception ratio (PRR), the received signal strength indicator (RSSI) and the link quality indicator (LQI) under diverse experimental settings. Some observations of this study are inconsistent with or even contradict prior results that are achieved in open fields or relatively clean environments and thus, provide new insights both into effectively evaluating the low-power wireless links and into efficiently deploying wireless sensor network systems in forest environments. PMID:27355957

  7. Optical Communication System for an Underwater Wireless Sensor Network

    Science.gov (United States)

    Gabriel, C.; Khalighi, A.; Bourennane, S.; Léon, P.; Rigaud, V.

    2012-04-01

    Seventy percent of the Earth is covered with water. Yet, we know so little about what lies below the sea surface. One new emerging technology that can help in oceans exploration is underwater wireless sensor network (UWSN). In such a network, a number of sensors are connected to a set of nodes that collect the data from them. Then, each node communicate its retrieved data to the other parts of the network through wireless links. So, an important step in the implementation of an UWSN is the design of an adequate transmitter/receiver system that is reliable, easy to implement, energy efficient and adapted to the underwater environment. Thanks to its cost-effectiveness and low-energy consumption property, optical underwater communication turns to be the most adequate solution for medium range node connections in an UWSN. To evaluate the optical underwater channel, we have studied its impulse response using a Monte Carlo simulator that takes into consideration all the transmitter, receiver and medium characteristics. We have demonstrated through these simulations that the channel delay dispersion is negligible in most practical cases. Therefore, we do not need to perform computationally complex signal processing such as channel equalization at the receiver. After studying the channel characteristics, we have turned our attention onto the transmitter/receiver system design. For this, we have simulated a system composed by a high-power monochromatic 532 nm LED transmitter and a Silicon PIN photodiode receiver with a collimating lens for capturing the scattered light. After photo-detection, the photo-current is converted to a voltage and low-pass filtered to limit the thermal noise variance which is the dominant noise in the receiver. Note that, in our case, background noise can be neglected because we are working in deep waters were the sunlight cannot penetrate. Then, using on-off-keying (OOK) modulation, we have proceeded to signal detection based on optimum

  8. Space diversity techniques in indoor broadband optical wireless communications

    Science.gov (United States)

    Alqudah, Yazan A.

    Wireless optical (infrared) link provides a secure and a promising alternative to radio for wireless indoor connectivity, be it for terminals or sensors. The large spectrum of unregulated band enables a link to provide broadband access needed for multimedia and other bandwidth demanding applications. The spatial confinement of infrared light provides interference-free bandwidth-reuse in adjacent rooms. The ability to create spatially independent channels in a small physical space holds the promise of large link capacity. The main challenges in the design of an infrared link include: susceptibility to shadowing, multipath dispersion, and limited range resulting from noise generated by ambient light. Shadowing caused by benign objects blocking signal path results in service degradation, if not complete interruption. Configurations employing wide beam transmitter to service many receiver locations suffer multipath. Noise at receiver is generated by ambient light. Even in a uniformly lit environment, noise generated by natural and artificial light varies depending on receiver location and orientation. To combat the adverse effects of temporal dispersion in high-speed applications, an accurate channel impulse response is needed. The impulse response is used to analyze and to compensate for the effects of multipath dispersion. In this work, a new approach for obtaining the channel impulse response is presented resulting in tremendous savings in calculation time and bringing insight into the channel behavior. The ability to create spatially independent channels has motivated a new configuration called Multi-Spot Diffusing (MSD) configuration. In which, a transmitter acts as an array antenna, with each element transmitting data over an independent channel. A multibranch receiver is employed to receive independent copies of transmitted data through each of its branches. In our research, we analyze MSD link with the objective of determining the optimal number of branches

  9. Switched diversity approach for multireceiving optical wireless systems.

    Science.gov (United States)

    Moradi, Hassan; Refai, Hazem H; Lopresti, Peter G

    2011-10-10

    A number of existing spatial diversity schemes have been shown to improve the performance of optical wireless communication systems in diversity-rich environments. Among all, switched diversity has low complexity and is simple to implement. In this paper, an innovative spatial diversity scheme based on switched diversity is proposed. The scheme, namely switch-to-dominant combining, contributes to a higher bit error rate (BER) performance when compared to conventional switched diversity schemes, including switch-and-stay and switch-and-examine diversity. The optical multireceiver wireless system operates in a spatially correlated and lognormally distributed fading channel. Analytical analyses are conducted to demonstrate BER and processing load performance offered by the new scheme and compare them to available schemes, i.e., conventional switched combining and selection combining. © 2011 Optical Society of America

  10. Frequency-division multiplexer and demultiplexer for terahertz wireless links.

    Science.gov (United States)

    Ma, Jianjun; Karl, Nicholas J; Bretin, Sara; Ducournau, Guillaume; Mittleman, Daniel M

    2017-09-28

    The development of components for terahertz wireless communications networks has become an active and growing research field. However, in most cases these components have been studied using a continuous or broadband-pulsed terahertz source, not using a modulated data stream. This limitation may mask important aspects of the performance of the device in a realistic system configuration. We report the characterization of one such device, a frequency multiplexer, using modulated data at rates up to 10 gigabits per second. We also demonstrate simultaneous error-free transmission of two signals at different carrier frequencies, with an aggregate data rate of 50 gigabits per second. We observe that the far-field spatial variation of the bit error rate is different from that of the emitted power, due to a small nonuniformity in the angular detection sensitivity. This is likely to be a common feature of any terahertz communication system in which signals propagate as diffracting beams not omnidirectional broadcasts.There is growing interest in the development of components to facilitate wireless communications in the terahertz but the characterization of these systems involve an unmodulated input. Here the authors demonstrate multiplexing and demultiplexing of data streams in the terahertz range using a real data link.

  11. Wireless, Passive Encoded Saw Sensors and Communication Links - Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation proposed here is a complete, wireless remote sensing solution using passive SAW Orthogonal Frequency Coded (OFC) sensors and a wireless interrogation...

  12. A key technology for standardizing outdoor optical wireless communications

    Directory of Open Access Journals (Sweden)

    Yuwei Su

    2017-06-01

    Full Text Available In this paper, we introduce a key technology, polarization modulation (PM, which should be taken into account when standardizing outdoor optical wireless communications (OWC, also known as free-space optical communications (FSO. We analyze the distortion of the polarization state when a laser beam propagates through the atmospheric channel. The floating range of the optical polarization was estimated and the necessity of researching the proposed technology was discussed. Moreover, we conducted a comparison between the PM-based FSO system and intensity modulation-based FSO system. The conclusions will be helpful in establishing the FSO standard architectures.

  13. Information Theoretical Limits of Free-Space Optical Links

    KAUST Repository

    Ansari, Imran Shafique

    2016-08-25

    Generalized fading has been an imminent part and parcel of wireless communications. It not only characterizes the wireless channel appropriately but also allows its utilization for further performance analysis of various types of wireless communication systems. Under the umbrella of generalized fading channels, a unified ergodic capacity analysis of a free-space optical (FSO) link under both types of detection techniques (i.e., intensity modulation/direct detection (IM/DD) as well as heterodyne detection) over generalized atmospheric turbulence channels that account for generalized pointing errors is presented. Specifically, unified exact closed-form expressions for the moments of the end-to-end signal-to-noise ratio (SNR) of a single link FSO transmission system are presented. Subsequently, capitalizing on these unified statistics, unified exact closed-form expressions for ergodic capacity performance metric of FSO link transmission systems is offered. Additionally, for scenarios wherein the exact closed-form solution is not possible to obtain, some asymptotic results are derived in the high SNR regime. All the presented results are verified via computer-based Monte-Carlo simulations.

  14. Experimental Performance Analysis of Wireless Links for Healthcare ...

    African Journals Online (AJOL)

    Wireless networking is currently being deployed for various applications. However, the application of wireless networking in healthcare remains a challenge mainly because of security and reliability concerns. This paper presents experimental results of performance analysis of a wireless network for healthcare application ...

  15. Distortion-Based Link Adaptation for Wireless Video Transmission

    Directory of Open Access Journals (Sweden)

    Andrew Nix

    2008-06-01

    Full Text Available Wireless local area networks (WLANs such as IEEE 802.11a/g utilise numerous transmission modes, each providing different throughputs and reliability levels. Most link adaptation algorithms proposed in the literature (i maximise the error-free data throughput, (ii do not take into account the content of the data stream, and (iii rely strongly on the use of ARQ. Low-latency applications, such as real-time video transmission, do not permit large numbers of retransmission. In this paper, a novel link adaptation scheme is presented that improves the quality of service (QoS for video transmission. Rather than maximising the error-free throughput, our scheme minimises the video distortion of the received sequence. With the use of simple and local rate distortion measures and end-to-end distortion models at the video encoder, the proposed scheme estimates the received video distortion at the current transmission rate, as well as on the adjacent lower and higher rates. This allows the system to select the link-speed which offers the lowest distortion and to adapt to the channel conditions. Simulation results are presented using the MPEG-4/AVC H.264 video compression standard over IEEE 802.11g. The results show that the proposed system closely follows the optimum theoretic solution.

  16. mm-Wave Hybrid Photonic Wireless Links for Ultra-High Speed Wireless Transmissions

    DEFF Research Database (Denmark)

    Rommel, Simon; Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

    Hybrid photonic-wireless transmission schemes in the mm-wave frequency range are promising candidates to enable the multi-gigabit per second data communications required from wireless and mobile networks of the 5th and future generations. Large FCC spectrum allocations for wireless transmission...

  17. Acemind new indoor full duplex optical wireless communication prototype

    Science.gov (United States)

    Bouchet, Olivier; Perrufel, Micheline; Topsu, Suat; Guan, Hongyu

    2016-09-01

    For over a century and Mr. Guglielmo Marconi invention, systems using radio waves have controlled over wireless telecommunication solutions; from Amplitude Modulation (AM) radio products to satellite communications for instance. But beyond an increasingly negative opinion face to radio waves and radio spectrum availability more and more reduced; there is an unprecedented opportunity with LED installation in displays and lighting to provide optical wireless communication solutions. As a result, technologically mature solutions are already commercially available for services such as Location Based Services (LBS), broadcast diffusion or Intelligent Transport Services (ITS). Pending finalization of the standard review process IEEE 802.15.7 r1, our paper presents the results of the European collaborative project named "ACEMIND". It offers an indoor bilateral optical wireless communication prototype having the following characteristics: use of the existing electrical infrastructure, through judicious combination with Light Fidelity (LiFi), Power Line Communication (PLC) and Ethernet to reduce the implementation cost. We propose a bilateral optical wireless communication even when the light is switched off by using Visible Light Communication (VLC) and Infra-Red Communication (IRC) combined to a remote optical switch. Dimensionally optimized LiFi module is presented in order to offer the possibility for integration inside a laptop. Finally, there is operational mechanism implementation such as OFDM/DMT to increase throughput. After the introduction, we will present the results of a market study from Orange Labs customers about their opinion on LiFi components. Then we will detail the LiFi prototype, from the physical layer aspect to MAC layer before concluding on commercial development prospects.

  18. THz photonic wireless links with 16-QAM modulation in the 375-450 GHz band

    DEFF Research Database (Denmark)

    Jia, Shi; Yu, Xianbin; Hu, Hao

    2016-01-01

    We propose and experimentally demonstrate THz photonic wireless communication systems with 16-QAM modulation in the 375-450 GHz band. The overall throughput reaches as high as 80 Gbit/s by exploiting four THz channels with 5 Gbaud 16-QAM baseband modulation per channel. We create a coherent optic...... signal transmitter and the THz wireless transmitter with negligible induced power penalty....

  19. 60-GHz optical/wireless MIMO system integrated with optical subcarrier multiplexing and 2x2 wireless communication.

    Science.gov (United States)

    Lin, Chi-Hsiang; Lin, Chun-Ting; Huang, Hou-Tzu; Zeng, Wei-Siang; Chiang, Shou-Chih; Chang, Hsi-Yu

    2015-05-04

    This paper proposes a 2x2 MIMO OFDM Radio-over-Fiber scheme based on optical subcarrier multiplexing and 60-GHz MIMO wireless transmission. We also schematically investigated the principle of optical subcarrier multiplexing, which is based on a dual-parallel Mach-Zehnder modulator (DP-MZM). In our simulation result, combining two MIMO OFDM signals to drive DP-MZM gives rise to the PAPR augmentation of less than 0.4 dB, which mitigates nonlinear distortion. Moreover, we applied a Levin-Campello bit-loading algorithm to compensate for the uneven frequency responses in the V-band. The resulting system achieves OFDM signal rates of 61.5-Gbits/s with BER of 10(-3) over 25-km SMF transmission followed by 3-m wireless transmission.

  20. Miniaturised wireless smart tag for optical chemical analysis applications.

    Science.gov (United States)

    Steinberg, Matthew D; Kassal, Petar; Tkalčec, Biserka; Murković Steinberg, Ivana

    2014-01-01

    A novel miniaturised photometer has been developed as an ultra-portable and mobile analytical chemical instrument. The low-cost photometer presents a paradigm shift in mobile chemical sensor instrumentation because it is built around a contactless smart card format. The photometer tag is based on the radio-frequency identification (RFID) smart card system, which provides short-range wireless data and power transfer between the photometer and a proximal reader, and which allows the reader to also energise the photometer by near field electromagnetic induction. RFID is set to become a key enabling technology of the Internet-of-Things (IoT), hence devices such as the photometer described here will enable numerous mobile, wearable and vanguard chemical sensing applications in the emerging connected world. In the work presented here, we demonstrate the characterisation of a low-power RFID wireless sensor tag with an LED/photodiode-based photometric input. The performance of the wireless photometer has been tested through two different model analytical applications. The first is photometry in solution, where colour intensity as a function of dye concentration was measured. The second is an ion-selective optode system in which potassium ion concentrations were determined by using previously well characterised bulk optode membranes. The analytical performance of the wireless photometer smart tag is clearly demonstrated by these optical absorption-based analytical experiments, with excellent data agreement to a reference laboratory instrument. © 2013 Elsevier B.V. All rights reserved.

  1. Low complexity source and channel coding for mm-wave hybrid fiber-wireless links

    DEFF Research Database (Denmark)

    Lebedev, Alexander; Vegas Olmos, Juan José; Pang, Xiaodan

    2014-01-01

    We report on the performance of channel and source coding applied for an experimentally realized hybrid fiber-wireless W-band link. Error control coding performance is presented for a wireless propagation distance of 3 m and 20 km fiber transmission. We report on peak signal-to-noise ratio perfor...

  2. Centralized optical-frequency-comb-based RF carrier generator for DWDM fiber-wireless access systems

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Beltran, Marta; Sanchez, Jose

    2014-01-01

    In this paper, we report on a gigabit capacity fiber-wireless system that enables smooth integration between high-speed wireless networks and dense wavelength-division-multiplexing (DWDM) access networks. By employing a centralized optical frequency comb, both the wireline and the wireless servic...

  3. Integrated control platform for converged optical and wireless networks

    DEFF Research Database (Denmark)

    Yan, Ying

    The next generation of broadband access networks is expected to be heterogeneous. Multiple wired and wireless systems can be integrated, in order to simultaneously provide seamless access with an appropriate Quality of Service (QoS). Wireless networks support ubiquitous connectivity yet low data...... control platform design. To achieve an integrated and unified control platform, enhanced signalling protocol plays an important role in gluing the two different technologies. Consequently, an integrated resource management system is developed. Furthermore, and admission control scheme for connections...... are distributed based on the network states, channel conditions, and QoS requirements. A new aspect in the design of future network is the energy efficiency. An energy management mechanism is proposed and evaluated for the optical network. With regard to power saving, a sleep mode operation is developed...

  4. A 400 Gbps/100 m free-space optical link

    Science.gov (United States)

    Lin, Chun-Yu; Lu, Hai-Han; Ho, Chun-Ming; Cheng, Ming-Te; Huang, Sheng-Jhe; Wang, Yun-Chieh; Chi, Jing-Kai

    2017-02-01

    A 400 Gbps/100 m free-space optical (FSO) link with dense-wavelength-division-multiplexing (DWDM)/space-division-multiplexing (SDM) techniques and a doublet lens scheme is proposed. To the best of our knowledge, this is the first time that a link adopting DWDM and SDM techniques and a doublet lens scheme has demonstrated a 400 Gbps/100 m FSO link. The experimental results show that the free-space transmission rate is significantly enhanced by the DWDM and SDM techniques, and the free-space transmission distance is greatly increased by the doublet lens scheme. A 16-channel FSO link with a total transmission rate of 400 Gbps (25 Gbps/λ  ×  16 λ  =  400 Gbps) over a 100 m free-space link is successfully demonstrated. Such a 400 Gbps/100 m DWDM/SDM FSO link provides the advantages of optical wireless communications for high transmission rates and long transmission distances, which is very useful for high-speed and long-haul light-based WiFi (LiFi) applications.

  5. High-speed duplex optical wireless communication system for indoor personal area networks.

    Science.gov (United States)

    Wang, Ke; Nirmalathas, Ampalavanapillai; Lim, Christina; Skafidas, Efstratios

    2010-11-22

    In this paper a new hybrid wireless access system incorporating high bandwidth line-of-sight free space optical wireless and radio frequency localization is proposed and demonstrated. This system is capable of supporting several gigabits/second up-stream and down-stream data transmission and ideally suited for high bandwidth indoor applications such as personal area networks. A radio frequency signal is used to achieve localization of subscribers, offering limited mobility to subscribers within a practical office scenario. Even with the modest transmitted power of 5 dBm, we demonstrate satisfactory performance of bit error rates better than 10(-9) over the entire room in the presence of strong background light. Using simulations, the effectiveness of the proposed system architecture is investigated and the key performance trade-offs identified. Proof-of-concept experiments have also been carried out to validate simulation model, and initial experimental results successfully demonstrate the feasibility of the system capable of supporting 2.5 Gbps over a 1-2 m optical wireless link (limited by the length of the sliding rail used in the experiment) with a 45 degrees diffused beam in an indoor environment for the first time.

  6. R&D Towards Cryogenic Optical Links

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, M.; Radeka, V.; Galea, R.; Gong, D.; Hou, S.; Lissauer, D.; Liu, C.; Liu, T.; Rehak, P.; Sondericker, J.; Stroynowski, R.; Su, D.-S., Takacs, P.; Takai, H.; Techerniatine, V.; Teng, P.-K.; Thorn, C.; Xiang, A.C.; Ye, J.; Yu, B.

    2010-12-15

    A number of critical active and passive components of optical links have been tested at 77 K or lower temperatures, demonstrating potential development of optical links operating inside the liquid argon time projection chamber (LArTPC) detector cryostat. A ring oscillator, individual MOSFETs, and a high speed 16:1 serializer fabricated in a commercial 0.25-{micro}m silicon-on-sapphire CMOS technology continued to function from room temperature to 4.2 K, 15 K, and 77 K respectively. Three types of laser diodes lase from room temperature to 77 K. Optical fibers and optical connectors exhibited minute attenuation changes from room temperature to 77 K.

  7. R and D towards cryogenic optical links

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, M [Department of Electrical Engineering, Southern Methodist University, Dallas TX 75275 (United States); Galea, R [Department of Physics, Columbia University, New York, NY 10027 (United States); Gong, D; Liu, C; Liu, T; Sondericker, J; Stroynowski, R; Xiang, A C; Ye, J [Department of Physics, Southern Methodist University, Dallas TX 75275 (United States); Hou, S; Su, D-S; Teng, P-K [Institute of Physics, Academia Sinica, Nangang 11529, Taipei, Taiwan (China); Lissauer, D; Takai, H; Tcherniatine, V; Thorn, C [Physics Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Radeka, V; Rehak, P; Takacs, P; Yu, B, E-mail: kentl@smu.edu [Instrumentation Division, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2010-12-15

    A number of critical active and passive components of optical links have been tested at 77 K or lower temperatures, demonstrating potential development of optical links operating inside the liquid argon time projection chamber (LArTPC) detector cryostat. A ring oscillator, individual MOSFETs, and a high speed 16:1 serializer fabricated in a commercial 0.25-{mu}m silicon-on-sapphire CMOS technology continued to function from room temperature to 4.2 K, 15 K, and 77 K respectively. Three types of laser diodes lase from room temperature to 77 K. Optical fibers and optical connectors exhibited minute attenuation changes from room temperature to 77 K.

  8. R&D towards cryogenic optical links

    Science.gov (United States)

    Christiansen, M.; Galea, R.; Gong, D.; Hou, S.; Lissauer, D.; Liu, C.; Liu, T.; Radeka, V.; Rehak, P.; Sondericker, J.; Stroynowski, R.; Su, D.-S.; Takacs, P.; Takai, H.; Tcherniatine, V.; Teng, P.-K.; Thorn, C.; Xiang, A. C.; Ye, J.; Yu, B.

    2010-12-01

    A number of critical active and passive components of optical links have been tested at 77 K or lower temperatures, demonstrating potential development of optical links operating inside the liquid argon time projection chamber (LArTPC) detector cryostat. A ring oscillator, individual MOSFETs, and a high speed 16:1 serializer fabricated in a commercial 0.25-μm silicon-on-sapphire CMOS technology continued to function from room temperature to 4.2 K, 15 K, and 77 K respectively. Three types of laser diodes lase from room temperature to 77 K. Optical fibers and optical connectors exhibited minute attenuation changes from room temperature to 77 K.

  9. R and D Towards Cryogenic Optical Links

    International Nuclear Information System (INIS)

    Christiansen, M.; Radeka, V.; Galea, R.; Gong, D.; Hou, S.; Lissauer, D.; Liu, C.; Liu, T.; Rehak, P.; Sondericker, J.; Stroynowski, R.; Su, D.-S.; Takacs, P.; Takai, H.; Techerniatine, V.; Teng, P.-K.; Thorn, C.; Xiang, A.C.; Ye, J.; Yu, B.

    2010-01-01

    A number of critical active and passive components of optical links have been tested at 77 K or lower temperatures, demonstrating potential development of optical links operating inside the liquid argon time projection chamber (LArTPC) detector cryostat. A ring oscillator, individual MOSFETs, and a high speed 16:1 serializer fabricated in a commercial 0.25-(micro)m silicon-on-sapphire CMOS technology continued to function from room temperature to 4.2 K, 15 K, and 77 K respectively. Three types of laser diodes lase from room temperature to 77 K. Optical fibers and optical connectors exhibited minute attenuation changes from room temperature to 77 K.

  10. Diversity Order Results for MIMO Optical Wireless Communications

    KAUST Repository

    Sapenov, Yerzhan

    2017-09-21

    An optical wireless multiple-input multiple-output (MIMO) communication system employing intensity-modulation direct-detection (IM/DD) is considered. The maximal diversity order of the channel is characterized by studying the outage probability. Then, spatial repetition coding (RC) is shown to be diversity-optimal as it achieves the channel’s maximal diversity order. This diversity order is given by a simple expression which is suitable for any channel statistics of practical interest. The results are specialized to some practical channel statistics, and numerical results are provided to verify the results.

  11. Underwater wireless optical communications: From system-level demonstrations to channel modelling

    KAUST Repository

    Oubei, Hassan M.

    2018-01-09

    In this paper, we discuss about recent experimental advances in underwater wireless optical communications (UWOC) over various underwater channel water types using different modulation schemes as well as modelling and describing the statistical properties of turbulence-induced fading in underwater wireless optical channels using laser beam intensity fluctuations measurements.

  12. Efficient Weibull channel model for salinity induced turbulent underwater wireless optical communications

    KAUST Repository

    Oubei, Hassan M.

    2017-12-13

    Recent advances in underwater wireless optical communications necessitate a better understanding of the underwater channel. We propose the Weibull model to characterize the fading of salinity induced turbulent underwater wireless optical channels. The model shows an excellent agreement with the measured data under all channel conditions.

  13. Network Communication by Optical Directional Link

    Directory of Open Access Journals (Sweden)

    V. Biolkova

    1999-04-01

    Full Text Available In this article, infrared point-to-point technologies (optical directional links are discussed which are designed for digital transmissions. Optical directional links (ODLs are transparent for the SDH/ATM, FDDI-II, Ethernet, and Token Ring protocols. Depending on type, ODL ranges are 300 m, 500 m, 1000 m and 2000 m. Steady and statistical models of ODL are presented as well as the measuring ODL arrangement and the graphs concerning the fluctuations of the received signal.

  14. Photonics-assisted wireless link based on mm-wave reconfigurable antennas

    DEFF Research Database (Denmark)

    Feliciano daCosta, Igor; Cerqueira Sodré, Arismar; Rodriguez Páez, Juan Sebastián

    2017-01-01

    The authors report a novel concept for photonics-assisted and broadband optical-wireless indoor networks based on optically-controlled reconfigurable antenna arrays (OCRAAs) and photonic down conversion (PDC) techniques, operating in the 28 and 38 GHz frequency bands. The antenna bandwidth is opt...... for access networks in the mm-wave frequency range....

  15. Ultrafast transient responses of optical wireless communication detectors.

    Science.gov (United States)

    Jin, Xian; Collier, Christopher M; Garbowski, Jamieson J A; Born, Brandon; Holzman, Jonathan F

    2013-07-10

    In this work, fundamental ultrafast transient responses are studied for optical wireless communication (OWC) detectors. It is shown that material impulse responses, associated with transient photoconductivity, and geometrical input responses, associated with transient optical power, must be considered in tandem when OWC photodetection is pursued with broad spectral and directional characteristics. An OWC detector, composed of GaAs photoconductive gaps in a corner-cube geometry, is fabricated and analyzed. The GaAs material response times are investigated experimentally and found to range from approximately 3 ps to 200 fs for 390 nm (violet) to 780 nm (red) photoexcitation. The geometrical response times are investigated theoretically and found to range from approximately 2 to 20 ps for device dimensions from 1 to 10 mm. The overall response times manifest themselves in two distinct dimensional regimes, with differing levels of wavelength and dimension dependence. The relevance of these findings is discussed for future ultrafast OWC detectors.

  16. Non-line-of-sight optical wireless sensor network operating in multiscattering channel

    Science.gov (United States)

    Kedar, Debbie; Arnon, Shlomi

    2006-11-01

    Networks of sensors are envisaged to be major participants in future data-gathering systems for civilian and military applications, including medical and environmental monitoring and surveillance, home security, agriculture, and industry. Typically, a very large number of miniature sensing and communicating nodes are distributed ad hoc at the location of interest, where they establish a network and wirelessly communicate sensed data either to one another or to a base station using various network topologies. The optical modality is a potential solution for the links, due to the small and lightweight hardware and low power consumption, as well as other special features. Notably, the backscattering of light by molecules and aerosols in the atmosphere can function as a vehicle of communication in a way similar to the deployment of numerous tiny reflecting mirrors. The scattering of light at solar-blind ultraviolet wavelengths is of particular interest since scattering by atmospheric particles is significant and ambient solar interference is minimal. In this paper we derive a mathematical model of a simple and low-cost non-line-of-sight (NLOS) optical wireless sensor network operating in the solar-blind ultraviolet spectral range. The viability and limitations of the internode link are evaluated and found to facilitate miniature operational sensor networks.

  17. High speed optical wireless data transmission system for particle sensors in high energy physics

    Science.gov (United States)

    Ali, W.; Corsini, R.; Ciaramella, E.; Dell'Orso, R.; Messineo, A.; Palla, F.

    2015-08-01

    High speed optical fiber or copper wire communication systems are frequently deployed for readout data links used in particle physics detectors. Future detector upgrades will need more bandwidth for data transfer, but routing requirements for new cables or optical fiber will be challenging due to space limitations. Optical wireless communication (OWC) can provide high bandwidth connectivity with an advantage of reduced material budget and complexity of cable installation and management. In a collaborative effort, Scuola Superiore Sant'Anna and INFN Pisa are pursuing the development of a free-space optical link that could be installed in a future particle physics detector or upgrade. We describe initial studies of an OWC link using the inner tracker of the Compact Muon Solenoid (CMS) detector as a reference architecture. The results of two experiments are described: the first to verify that the laser source transmission wavelength of 1550 nm will not introduce fake signals in silicon strip sensors while the second was to study the source beam diameter and its tolerance to misalignment. For data rates of 2.5 Gb/s and 10 Gb/s over a 10 cm working distance it was observed that a tolerance limit of ±0.25 mm to ±0.8 mm can be obtained for misaligned systems with source beam diameters of 0.38 mm to 3.5 mm, respectively.

  18. Performance prediction of a synchronization link for distributed aerospace wireless systems.

    Science.gov (United States)

    Wang, Wen-Qin; Shao, Huaizong

    2013-01-01

    For reasons of stealth and other operational advantages, distributed aerospace wireless systems have received much attention in recent years. In a distributed aerospace wireless system, since the transmitter and receiver placed on separated platforms which use independent master oscillators, there is no cancellation of low-frequency phase noise as in the monostatic cases. Thus, high accurate time and frequency synchronization techniques are required for distributed wireless systems. The use of a dedicated synchronization link to quantify and compensate oscillator frequency instability is investigated in this paper. With the mathematical statistical models of phase noise, closed-form analytic expressions for the synchronization link performance are derived. The possible error contributions including oscillator, phase-locked loop, and receiver noise are quantified. The link synchronization performance is predicted by utilizing the knowledge of the statistical models, system error contributions, and sampling considerations. Simulation results show that effective synchronization error compensation can be achieved by using this dedicated synchronization link.

  19. Wireless Mobile Computing and its Links to Descriptive Complexity

    Czech Academy of Sciences Publication Activity Database

    Wiedermann, Jiří; Pardubská, D.

    2008-01-01

    Roč. 19, č. 4 (2008), s. 887-913 ISSN 0129-0541 R&D Projects: GA AV ČR 1ET100300517 Institutional research plan: CEZ:AV0Z10300504 Keywords : alternating Turing machine * simulation * simultaneous time-space complexity * wireless parallel Turing machine Subject RIV: IN - Informatics, Computer Science Impact factor: 0.554, year: 2008

  20. Optical Wireless Sensor Network System Using Corner Cube Retroreflectors

    Directory of Open Access Journals (Sweden)

    Teramoto Shota

    2005-01-01

    Full Text Available We analyze an optical wireless sensor network system that uses corner cube retroreflectors (CCRs. A CCR consists of three flat mirrors in a concave configuration. When a light beam enters the CCR, it bounces off each of the three mirrors, and is reflected back parallel to the direction it entered. A CCR can send information to the base station by modulating the reflected beam by vibrating the CCR or interrupting the light path; the most suitable transmission format is on-off keying (OOK. The CCR is attractive in many optical communication applications because it is small, easy to operate, and has low power consumption. This paper examines two signal decision schemes for use at the base station: collective decision and majority decision. In collective decision, all optical signals detected by the sensors are received by one photodetector (PD, and its output is subjected to hard decision. In majority decision, the outputs of the PDs associated with the sensors are subjected to hard detection, and the final data is decided by majority decision. We show that increasing the number of sensors improves the bit error rate (BER. We also show that when the transmitted optical power is sufficiently large, BER depends on sensor accuracy. We confirm that collective decision yields lower BERs than majority decision.

  1. Localization of Energy Harvesting Empowered Underwater Optical Wireless Sensor Networks

    KAUST Repository

    Saeed, Nasir

    2017-12-20

    In this paper, a received signal strength (RSS) based localization technique is developed for energy harvesting underwater optical wireless sensor networks (EH-UOWSNs), where the optical noise sources and channel impairments of seawater pose significant challenges for range estimation. Energy limitation is another major problem due to the limited battery power and difficulty in replacing or recharging the battery of an underwater sensor node. In the proposed framework, sensor nodes with insufficient battery, harvest the energy and starts communicating once it has sufficient energy storage. Network localization is carried out by measuring the RSSs of active nodes, which are modeled based on the underwater optical communication channel characteristics. Thereafter, block kernel matrices are computed for the RSS based range measurements. Unlike the traditional shortest-path approach, the proposed technique reduces the shortest path estimation for each block kernel matrix. Once the complete block kernel matrices are available, a closed form localization technique is developed to find the location of every optical sensor node in the network. Furthermore, an analytical expression for Cramer Rao lower bound (CRLB) is derived as a benchmark to compare the localization performance of the proposed technique. Finally, extensive simulations show that the proposed technique outperforms the well-known network localization techniques.

  2. Automated alignment system for optical wireless communication systems using image recognition.

    Science.gov (United States)

    Brandl, Paul; Weiss, Alexander; Zimmermann, Horst

    2014-07-01

    In this Letter, we describe the realization of a tracked line-of-sight optical wireless communication system for indoor data distribution. We built a laser-based transmitter with adaptive focus and ray steering by a microelectromechanical systems mirror. To execute the alignment procedure, we used a CMOS image sensor at the transmitter side and developed an algorithm for image recognition to localize the receiver's position. The receiver is based on a self-developed optoelectronic integrated chip with low requirements on the receiver optics to make the system economically attractive. With this system, we were able to set up the communication link automatically without any back channel and to perform error-free (bit error rate <10⁻⁹) data transmission over a distance of 3.5 m with a data rate of 3 Gbit/s.

  3. Gigabit-class optical wireless communication system at indoor distances (1.5 ÷ 4 m).

    Science.gov (United States)

    Cossu, Giulio; Ali, Wajahat; Corsini, Raffaele; Ciaramella, Ernesto

    2015-06-15

    In this paper we experimentally realized bidirectional optical wireless communication (OWC) link using four channel visible LED board exploiting wavelength division multiplexing (WDM) for the downlink and infrared LED for uplink. We achieved greater than 5 Gbit/s data rate at common indoor distance (1.5 to 4 m) for downlink and 1.5 Gbit/s for uplink using commercially available LEDs. We achieved these results after a careful choice of the LED emission wavelengths and the optical filter spectra. Moreover, we investigate the optimal LED working current and the optimal modulation depth. The bit error ratios of all the channels were maintained lower than the FEC limit (3.8·10(-3)).

  4. Underwater wireless optical MIMO system with spatial modulation and adaptive power allocation

    Science.gov (United States)

    Huang, Aiping; Tao, Linwei; Niu, Yilong

    2018-04-01

    In this paper, we investigate the performance of underwater wireless optical multiple-input multiple-output communication system combining spatial modulation (SM-UOMIMO) with flag dual amplitude pulse position modulation (FDAPPM). Channel impulse response for coastal and harbor ocean water links are obtained by Monte Carlo (MC) simulation. Moreover, we obtain the closed-form and upper bound average bit error rate (BER) expressions for receiver diversity including optical combining, equal gain combining and selected combining. And a novel adaptive power allocation algorithm (PAA) is proposed to minimize the average BER of SM-UOMIMO system. Our numeric results indicate an excellent match between the analytical results and numerical simulations, which confirms the accuracy of our derived expressions. Furthermore, the results show that adaptive PAA outperforms conventional fixed factor PAA and equal PAA obviously. Multiple-input single-output system with adaptive PAA obtains even better BER performance than MIMO one, at the same time reducing receiver complexity effectively.

  5. A novel optical single-sideband frequency translation technique for transmission of wireless MIMO signals over fiber-wireless system

    Science.gov (United States)

    Shaddad, Redhwan Q.; Mohammad, Abu Bakar; Al-Hetar, Abdulaziz M.; Al-Gailani, Samir A.

    2013-04-01

    The fiber-wireless (FiWi) access network is a powerful hybrid architecture of optical backhaul and wireless front-end to support high data rates and throughput with minimal time delay. By using radio over fiber (ROF) technique, the optical fiber is well adapted to propagate multiple wireless services having different carrier frequencies. However, multiple wireless signals which have the same carrier frequency cannot propagate over a single optical fiber on the same wavelength, such as multi-input multi-output (MIMO) signals. A novel optical single-sideband frequency translation technique is designed and simulated to solve this problem. 240 Mb/s 802.11n MIMO signals are proposed to transport over FiWi system using the proposed approach at 2.4 GHz and 5.0 GHz carrier frequencies. The crosstalk between MIMO signals with the same carrier frequency is excluded, since each MIMO signal is carried on a specific optical wavelength. Error vector magnitude (EVM) values of -29.83 dB (for 2.4 GHz) and -28.41 dB (for 5.0 GHz) have been achieved for bit error rate (BER) 10-5 in the proposed FiWi system.

  6. Encoding an Optical Signal using a Wireless Radio-Freqency Signal

    DEFF Research Database (Denmark)

    2011-01-01

    Source: US2012148252A The present invention provides a method for modulating an optical signal in a semiconductor device. A wireless radio frequency modulation signal is used to provide a time-dependent electric field in a semiconductor nanostructure region, which causes a change in the absorption...... in the semiconductor device. An optical signal propagating in the semiconductor device will be modulated in accordance with the properties of the wireless radio frequency modulation signal, thus providing a method for encoding information from a wireless radio frequency signal onto an optical carrier....

  7. GHz wireless On-off-Keying link employing all photonic RF carrier generation and digital coherent detection

    DEFF Research Database (Denmark)

    Sambaraju, Rakesh; Zibar, Darko; Caballero Jambrina, Antonio

    2010-01-01

    Gb/s wireless signals at 82, 88 and 100 GHz carrier frequencies are successfully generated by heterodyne mixing of two optical carriers. A photonic detection technique with optical coherent receiver and digital signal processing is implemented for signal demodulation....

  8. Experimental demonstration of MIMO-OFDM underwater wireless optical communication

    Science.gov (United States)

    Song, Yuhang; Lu, Weichao; Sun, Bin; Hong, Yang; Qu, Fengzhong; Han, Jun; Zhang, Wei; Xu, Jing

    2017-11-01

    In this paper, we propose and experimentally demonstrate a multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) underwater wireless optical communication (UWOC) system, with a gross bit rate of 33.691 Mb/s over a 2-m water channel using low-cost blue light-emitting-diodes (LEDs) and 10-MHz PIN photodiodes. The system is capable of realizing robust data transmission within a relatively large reception area, leading to relaxed alignment requirement for UWOC. In addition, we have compared the system performance of repetition coding OFDM (RC-OFDM), Alamouti-OFDM and multiple-input single-output OFDM (MISO-OFDM) in turbid water. Results show that the Alamouti-OFDM UWOC is more resistant to delay than the RC-OFDM-based system.

  9. Performance analysis of coherent wireless optical communications with atmospheric turbulence.

    Science.gov (United States)

    Niu, Mingbo; Song, Xuegui; Cheng, Julian; Holzman, Jonathan F

    2012-03-12

    Coherent wireless optical communication systems with heterodyne detection are analyzed for binary phase-shift keying (BPSK), differential PSK (DPSK), and M-ary PSK over Gamma-Gamma turbulence channels. Closed-form error rate expressions are derived using a series expansion approach. It is shown that, in the special case of K-distributed turbulence channel, the DPSK incurs a 3 dB signal-to-noise ratio (SNR) penalty compared to BPSK in the large SNR regime. The outage probability is also obtained, and a detailed outage truncation error analysis is presented and used to assess the accuracy in system performance estimation. It is shown that our series error rate expressions are simple to use and highly accurate for practical system performance estimation.

  10. An underwater optical wireless communication system based on LED source

    Science.gov (United States)

    Rao, Jionghui; Wei, Wei; Wang, Feng; Zhang, Xiaohui

    2011-11-01

    Compared with other communication methods, optical wireless communication (OWC) holds the merits of higher transmitting rate and sufficient secrecy. So it is an efficacious communicating measure for data transmitting between underwater carriers. However, due to the water attenuation and the transmitter & the receiver (TX/RX) collimation, this application is restrained in underwater mobile carriers. A prototype for underwater OWC was developed, in which a high-powered green LED array was used as the light source which partly raveled the TX/RX collimation out. A small pumped-multiple-tube (PMT) was used as the detector to increase the communicating range, and FPGA chips were employed to code and decode the communicating data. The data rate of the prototype approached to 4 Mb/s at 8.4m and 1 Mb/s at 22m where voice and Morse communications were achieved in a scope of 30 degree TX/RX angle.

  11. Capacity bounds for parallel IM-DD optical wireless channels

    KAUST Repository

    Chaaban, Anas

    2016-07-26

    A system consisting of parallel intensity-modulation direct-detection optical wireless channels with a total average intensity constraint is studied. Capacity upper and lower bounds for this system are derived. If channel-state information is available at the transmitter, the bounds have to be optimized with respect to intensity allocation over the parallel channels. The optimization of the lower bound is non-convex, however, the Karush-Kuhn-Tucker conditions can be used to find a list of possible solutions one of which is optimal. The optimal solution can then be found by an exhaustive search algorithm, which is computationally expensive. To overcome this, we propose a low-complexity intensity allocation algorithm which is nearly optimal. The optimized capacity lower bound coincides with the capacity at high signal-to-noise ratio. © 2016 IEEE.

  12. IO-Link Wireless enhanced factory automation communication for Industry 4.0 applications

    Directory of Open Access Journals (Sweden)

    R. Heynicke

    2018-03-01

    Full Text Available In the context of the Industry 4.0 initiative, Cyber-Physical Production Systems (CPPS or Cyber Manufacturing Systems (CMS can be characterized as advanced networked mechatronic production systems gaining their added value by interaction with the ambient Industrial Internet of Things (IIoT. In this context appropriate communication technologies and standards play a vital role to realize the manifold potential improvements in the production process. One of these standards is IO-Link. In 2016 more than 5 million IO-Link nodes have been produced and delivered, still gaining increasing acceptance for the communication between sensors, actuators and the control level. The steadily increasing demand for more flexibility in automation solutions can be fulfilled using wireless technologies. With the wireless extension for the IO-Link standard, which will be presented in this article, maximum cycle times of 5 ms can be achieved with a probability that this limit will be exceeded to be at maximum one part per billion. Also roaming capabilities, wireless coexistence mechanisms and the possibility to include battery-powered or energy-harvesting sensors with very limited energy resources in the realtime network were defined. For system planning, setup, operation and maintenance, the standard engineering tools of IO-Link can be employed so that the backward compatibility with wired IO-Link solutions can be guaranteed. Interoperability between manufacturers is a key requirement for any communication standard, thus a procedure for IO-Link Wireless testing is also suggested.

  13. Optical Transmission Schemes for GEO Feeder Links

    OpenAIRE

    Cowley, William; Giggenbach, Dirk; Mata Calvo, Ramon

    2014-01-01

    A novel transmission scheme for the forward link of a broadband satellite system that aims to avoid the need for feeder-link RF spectrum is described1. The hybrid scheme uses one or more optical uplinks from a hub station to geostationary satellite, plus one or more Ka band downlinks. The approach aims to retain the advantages of strong channel coding with high spectral efficiency, as used in recent high-speed digital video broadcast satellites, yet minimise on-boar...

  14. Remote Access Unit for Optic-to-Wireless Conversion

    DEFF Research Database (Denmark)

    Chorchos, Łukasz; Rommel, Simon; Turkiewicz, J. P.

    In this paper we propose a design of a reconfigurable Remote Access Unit (RAU) interfacing optical dense wavelength division multiplexed (DWDM) networks with radio communication links. To generate a radio signal the device utilizes a principles of incoherent heterodyne signal upconversion...

  15. Invited Article: Channel performance for indoor and outdoor terahertz wireless links

    Science.gov (United States)

    Ma, Jianjun; Shrestha, Rabi; Moeller, Lothar; Mittleman, Daniel M.

    2018-05-01

    One of the most exciting future applications of terahertz technology is in the area of wireless communications. As 5G systems incorporating a standard for millimeter-wave wireless links approach commercial roll-out, it is becoming clear that even this new infrastructure will not be sufficient to keep pace with the rapidly increasing global demand for bandwidth. One favorable solution that is attracting increasing attention for subsequent generations of wireless technology is to use higher frequencies, above 100 GHz. The implementation of such links will require significant advances in hardware, algorithms, and architecture. Although numerous research groups are exploring aspects of this challenging problem, many basic questions remain unaddressed. Here, we present an experimental effort to characterize THz wireless links in both indoor and outdoor environments. We report measurements at 100, 200, 300, and 400 GHz, using a link with a data rate of 1 Gbit/s. We demonstrate both line-of-sight and non-line-of-sight (specular reflection) links off of interior building walls. This work represents a first step to establish the feasibility of using THz carrier waves for data transmission in diverse situations and environments.

  16. RFID-over-Fiber system for agricultural exploitations - Wireless track and trace with range extension using optical fiber

    DEFF Research Database (Denmark)

    Madsen, Peter; Suhr, Lau Frejstrup; Cavalcante, Lucas Costa Pereira

    2015-01-01

    This paper proposes and demonstrates an RFIDover-Fiber wireless track and trace system using active RFID tags and operating over distances up to 30 km of optical fiber and 35 meters of wireless readability......This paper proposes and demonstrates an RFIDover-Fiber wireless track and trace system using active RFID tags and operating over distances up to 30 km of optical fiber and 35 meters of wireless readability...

  17. SITHON: A Wireless Network of in Situ Optical Cameras Applied to the Early Detection-Notification-Monitoring of Forest Fires

    Science.gov (United States)

    Tsiourlis, Georgios; Andreadakis, Stamatis; Konstantinidis, Pavlos

    2009-01-01

    The SITHON system, a fully wireless optical imaging system, integrating a network of in-situ optical cameras linking to a multi-layer GIS database operated by Control Operating Centres, has been developed in response to the need for early detection, notification and monitoring of forest fires. This article presents in detail the architecture and the components of SITHON, and demonstrates the first encouraging results of an experimental test with small controlled fires over Sithonia Peninsula in Northern Greece. The system has already been scheduled to be installed in some fire prone areas of Greece. PMID:22408536

  18. Radiation-Hard Optical Link for SLHC

    CERN Document Server

    Gan, K K; Fernando, W; Kagan, H P; Kass, R D; Law, A; Lebbai, M R M; Rau, A; Rizatdinova, F K; Skubic, P L; Smith, D S

    2007-01-01

    We study the feasibility of fabricating an optical link for the SLHC ATLAS silicon tracker based on the current pixel optical link architecture. The electrical signals between the current pixel modules and the optical modules are transmitted via micro-twisted cables. The optical signals between the optical modules and the data acquisition system are transmitted via rad-hard SIMM fibres spliced to rad-tolerant GRIN fibres. The link has several nice features. We have measured the bandwidths of the transmission lines and the results indicate that the micro twisted-pair cables can transmit signals up to ~ 1 Gb/s. The fusion spliced fibre ribbon can transmit signals up to ~ 2 Gb/s as reported in the previous conference. We have irradiated VCSEL arrays with 24 GeV protons and find four types of VCSEL arrays from three vendors survive to the SLHC dosage. We have also demonstrated the feasibility of fabricating a novel opto-pack for housing VCSEL and PIN arrays with BeO as the substrate.

  19. LightFD: A Lightweight Flow Detection Mechanism for Traffic Grooming in Optical Wireless DCNs

    KAUST Repository

    Al-Ghadhban, Amer

    2018-05-05

    State of the art wireless technologies have recently shown a great potential for enabling re-configurable data center network (DCN) topologies by augmenting the cabling complexity and link inflexibility of traditional wired data centers (DCs). In this paper, we propose an optical traffic grooming (TG) method for mice flows (MFs) and elephant flows (EFs) in wireless DCNs which are interconnected with wavelength division multiplexing (WDM) capable free-space optical (FSO) links. Since handling the bandwidth-hungry EFs along with delay-sensitive MFs over the same network resources have undesirable consequences, proposed TG policy handles MFs and EFs over distinctive network resources. MFs/EFs destined to the same rack are groomed into larger rack-to-rack MF/EF flows over dedicated lightpaths whose routes and capacities are jointly determined in a load balancing manner. Performance evaluations of proposed TG policy show a significant throughput improvement thanks to efficient bandwidth utilization of the WDM-FSO links. As MFs and EFs are needed to be separated, proposed TG requires expeditious flow detection mechanisms which can immediately classify EFs with very high accuracy. Since these cannot be met by existing packet-sampling and port-mirroring based solutions, we propose a fast and lightweight in-network flow detection (LightFD) mechanism with perfect accuracy. LightFD is designed as a module on the Virtual-Switch/Hypervisor, which detects EFs based on acknowledgment sequence number of flow packets. Emulation results show that LightFD can provide up to 500 times faster detection speeds than the sampling-based methods with %100 detection precision. We also demonstrate that the EF detection speed has a considerable impact on achievable EF throughput.

  20. Wireless communication links for brain-machine interface applications

    Science.gov (United States)

    Larson, L.

    2016-05-01

    Recent technological developments have given neuroscientists direct access to neural signals in real time, with the accompanying ability to decode the resulting information and control various prosthetic devices and gain insight into deeper aspects of cognition. These developments - along with deep brain stimulation for Parkinson's disease and the possible use of electro-stimulation for other maladies - leads to the conclusion that the widespread use electronic brain interface technology is a long term possibility. This talk will summarize the various technical challenges and approaches that have been developed to wirelessly communicate with the brain, including technology constraints, dc power limits, compression and data rate issues.

  1. Stabilized Optical Fiber Links for the XFEL

    CERN Document Server

    Winter, Axel; Grawert, Felix J; Ilday, Fatih O; Kaertner, Franz X; Kim, Jung-Won; Schlarb, Holger; Schmidt, Bernhard

    2005-01-01

    The timing synchronization scheme for the European X-Ray free electron laser facility (XFEL) is based on the generation and distribution of sub-picosecond laser pulses with actively stabilized repetition rate which are used to synchronize local RF oscillators. An integral part of the scheme is the distribution of the optical pulse stream to parts of the facility via optical fiber links. The optical path length of the fiber has to be stabilized against short-term and long-term timing jitter due to environmental effects, such as temperature drifts and acoustic vibrations, to better than 10 fs for distances ranging from tens of meters to several kilometers. In this paper, we present first experimental results for signal transmission through a km-long fiber link with femtosecond stability.

  2. An Energy Efficient Adaptive Wireless Link for Farms based on IoT technologies

    DEFF Research Database (Denmark)

    Blaszczyk, Tomasz; Lynggaard, P.

    2015-01-01

    There is a huge demand for automation infrastructures that increase the efficiency and the commercial potential for the agricultural sector. One approach to achieve these objectives is deploying Internet of Things including its embedded wireless sensor network platform. However, deploying wireless...... sensors in the fields far from the farms provide some challenges in terms of transmit power, path loss, and lack of power. This paper explores the possibility to deploy an efficient low power adaptable wireless link which interfaces the Internet of Things infrastructure located on the farm. This new...... adaptable link element offers many benefits such as adaptable transmit time, powered from a sustainable source, and a variable size payload based on the farmers need....

  3. An Energy Efficient Adaptive Wireless Link for Farms based on IoT technologies

    DEFF Research Database (Denmark)

    Blaszczyk, tomasz; Lynggaard, Per

    2016-01-01

    There is a huge demand for automation infrastructures that increase the efficiency and the commercial potential for the agricultural sector. One approach to achieve these objectives is deploying Internet of Things including its embedded wireless sensor network platform. However, deploying wireless...... sensors in the fields far from the farms provide some challenges in terms of transmit power, path loss, and lack of power. This paper explores the possibility to deploy an efficient low power adaptable wireless link which interfaces the Internet of Things infrastructure located on the farm. This new...... adaptable link element offers many benefits such as adaptable transmit time, powered from a sustainable source, and a variable size payload based on the farmers need....

  4. 28 GHz Wireless Backhaul Transceiver Characterization and Radio Link Budget

    Directory of Open Access Journals (Sweden)

    Marko E. Leinonen

    2018-02-01

    Full Text Available Millimeter wave communication is one of the main disruptive technologies in upcoming 5G mobile networks. One of the first candidate applications, which will be commercially ready by 2020, is wireless backhaul links or wireless last mile communication. This paper provides an analysis of this use‐case from radio engineering and implementation perspectives. Furthermore, preliminary experimental results are shown for a proof‐of‐concept wireless backhaul solution developed within the EU‐KR 5GCHAMPION project, which will be showcased during the 2018 Winter Olympic Games in Korea. In this paper, we verify system level calculations and a theoretical link budget analysis with conductive and radiated over‐the‐air measurements. The results indicate that the implemented radio solution is able to achieve the target key performance indicator, namely, a 2.5 Gbps data rate on average, over a range of up to 200 m.

  5. Optimal training sequences for indoor wireless optical communications

    International Nuclear Information System (INIS)

    Wang, Jun-Bo; Jiao, Yuan; Song, Xiaoyu; Chen, Ming

    2012-01-01

    Since indoor wireless optical communication (WOC) systems can offer several potential advantages over their radio frequency counterparts, there has been a growing interest in indoor WOC systems. Influenced by the complicated optical propagation environment, there exist multipath propagation phenomena. In order to eliminate the effect of multipath propagation, much attention should be concentrated on the channel estimation in indoor WOC systems. This paper investigates optimal training sequences (TSs) for estimating a channel impulse response in indoor WOC systems. Based on the Cramer–Rao bound (CRB) theorem, an explicit form of search criterion is found. Optimum TSs are obtained and tabulated by computer search for different channel responses and TS lengths. Measured by mean square error (MSE) performance, channel estimation errors are also investigated. Simulation results show that the MSE of the channel estimator at the receiver can be reduced significantly by using the optimized TS set. Moreover, the longer the TS, the better the MSE performance that can be obtained when the channel order is fixed. (paper)

  6. Impact of a half-space interface on the wireless link between tiny sensor nodes

    NARCIS (Netherlands)

    Penkin, D.; Janssen, G.; Yarovoy, A.

    2014-01-01

    The power budget of a wireless link between two electrically small sensor nodes located close to an interface between two media is studied. The model includes both the propagation channel losses and input impedance of the radio frequency antennas. It is shown that a highly inductive half-space

  7. Energy-Efficient Link-Layer Jamming Attacks against Wireless Sensor Network MAC Protocols

    NARCIS (Netherlands)

    Law, Y.W.; Palaniswami, M; van Hoesel, L.F.W.; Doumen, J.M.; Hartel, Pieter H.; Havinga, Paul J.M.

    A typical wireless sensor node has little protection against radio jamming. The situation becomes worse if energy-efficient jamming can be achieved by exploiting knowledge of the data link layer. Encrypting the packets may help to prevent the jammer from taking actions based on the content of the

  8. Energy-Efficient Link-Layer Jamming Attacks against Wireless Sensor Network MAC Protocols

    NARCIS (Netherlands)

    Law, Y.W.; van Hoesel, L.F.W.; Doumen, J.M.; Hartel, Pieter H.; Havinga, Paul J.M.; Atluri, V.; Samarati, P.; Ning, P.; Du, W.

    2005-01-01

    A typical wireless sensor node has little protection against radio jamming. The situation becomes worse if energy efficient jamming can be achieved by exploiting knowledge of the data link layer. Encrypting the packets may help prevent the jammer from taking actions based on the content of the

  9. Energy-efficient link-layer jamming attacks against wireless sensor network MAC protocols

    NARCIS (Netherlands)

    van Hoesel, L.F.W.; Law, Y.W.; Doumen, J.M.; Hartel, Pieter H.; Havinga, Paul J.M.

    A typical wireless sensor node has little protection against radio jamming. The situation becomes worse if energy-efficient jamming can be achieved by exploiting knowledge of the data link layer. Encrypting the packets may help to prevent the jammer from taking actions based on the content of the

  10. BER Performance of Stratified ACO-OFDM for Optical Wireless Communications over Multipath Channel

    OpenAIRE

    Gebeyehu, Zelalem Hailu; Langat, Philip Kibet; Maina, Ciira Wa

    2018-01-01

    In intensity modulation/direct detection- (IM/DD-) based optical OFDM systems, the requirement of the input signal to be real and positive unipolar imposes a reduction of system performances. Among previously proposed unipolar optical OFDM schemes for optical wireless communications (OWC), asymmetrically clipped optical OFDM (ACO-OFDM) and direct current biased optical OFDM (DCO-OFDM) are the most accepted ones. But those proposed schemes experience either spectral efficiency loss or energy e...

  11. The design of the CMOS wireless bar code scanner applying optical system based on ZigBee

    Science.gov (United States)

    Chen, Yuelin; Peng, Jian

    2008-03-01

    The traditional bar code scanner is influenced by the length of data line, but the farthest distance of the wireless bar code scanner of wireless communication is generally between 30m and 100m on the market. By rebuilding the traditional CCD optical bar code scanner, a CMOS code scanner is designed based on the ZigBee to meet the demands of market. The scan system consists of the CMOS image sensor and embedded chip S3C2401X, when the two dimensional bar code is read, the results show the inaccurate and wrong code bar, resulted from image defile, disturber, reads image condition badness, signal interference, unstable system voltage. So we put forward the method which uses the matrix evaluation and Read-Solomon arithmetic to solve them. In order to construct the whole wireless optics of bar code system and to ensure its ability of transmitting bar code image signals digitally with long distances, ZigBee is used to transmit data to the base station, and this module is designed based on image acquisition system, and at last the wireless transmitting/receiving CC2430 module circuit linking chart is established. And by transplanting the embedded RTOS system LINUX to the MCU, an applying wireless CMOS optics bar code scanner and multi-task system is constructed. Finally, performance of communication is tested by evaluation software Smart RF. In broad space, every ZIGBEE node can realize 50m transmission with high reliability. When adding more ZigBee nodes, the transmission distance can be several thousands of meters long.

  12. Theoretical and experimental studies of polarization fluctuations over atmospheric turbulent channels for wireless optical communication systems.

    Science.gov (United States)

    Zhang, Jiankun; Ding, Shengli; Zhai, Huili; Dang, Anhong

    2014-12-29

    In wireless optical communications (WOC), polarization multiplexing systems and coherent polarization systems have excellent performance and wide applications, while its state of polarization affected by atmospheric turbulence is not clearly understood. This paper focuses on the polarization fluctuations caused by atmospheric turbulence in a WOC link. Firstly, the relationship between the polarization fluctuations and the index of refraction structure parameter is introduced and the distribution of received polarization angle is obtained through theoretical derivations. Then, turbulent conditions are adjusted and measured elaborately in a wide range of scintillation indexes (SI). As a result, the root-mean-square (RMS) variation and probability distribution function (PDF) of polarization angle conforms closely to that of theoretical model.

  13. Reconfigurable Digital Coherent Receiver for Hybrid Optical Fiber/Wireless Metro-Access Networks

    DEFF Research Database (Denmark)

    Arlunno, Valeria; Guerrero Gonzalez, Neil; Caballero Jambrina, Antonio

    Single reconfigurable DSP coherent receiver is experimentally demonstrated for mixed-format and bit-rates including QPSK, OFDM, IR-UWB for wireline and wireless signal types. Successful transmission and detection over a deployed fiber link is achieved.......Single reconfigurable DSP coherent receiver is experimentally demonstrated for mixed-format and bit-rates including QPSK, OFDM, IR-UWB for wireline and wireless signal types. Successful transmission and detection over a deployed fiber link is achieved....

  14. The design of equipment for optical power measurement in FSO link beam cross-section

    Science.gov (United States)

    Latal, Jan; David, Tomas; Wilfert, Otakar; Kolka, Zdenek; Koudelka, Petr; Hanacek, Frantisek; Vitasek, Jan; Siska, Petr; Skapa, Jan; Vasinek, Vladimir

    2012-06-01

    The free space optical links have found their major application in today's technological society. The demand for quality broadband is a must for all types of end users in these times. Because of the large jamming from wireless radio networks in non-licensed ISM bands, the free space optical links provide bridging of some densely populated urban areas. Their advantage is the high transmission rate for relatively long distances. However, the disadvantage is the dependence of free space optical links on atmospheric influences. Aired collimated optical beam passes through the atmospheric transmission environment and by its influence cause the deformation of the optical beam. Author's team decided to construct a special measuring device for measurement of optical power in FSO link beam cross-section. The equipment is mobile and can be rearranged and adjust according to the given location and placement of the FSO link at any time. The article describes the individual structural elements of the measuring equipment, its controlling and application for evaluation and adjustment of measuring steps. The graphs from optical power measurements in the beam cross-section of professional FSO links are presented at the end.

  15. Digital broadband linearization of optical links.

    Science.gov (United States)

    Lam, Daniel; Fard, Ali M; Buckley, Brandon; Jalali, Bahram

    2013-02-15

    We present a digital postprocessing linearization technique to efficiently suppress dynamic distortions added to a wideband signal in an analog optical link. Our technique achieves up to 35 dB suppression of intermodulation distortions over multiple octaves of signal bandwidth. In contrast to conventional linearization methods, it does not require excessive analog bandwidth for performing digital correction. This is made possible by regenerating undesired distortions from the captured output, and subtracting it from the distorted digitized signal. Moreover, we experimentally demonstrate a record spurious-free dynamic range of 120 dB·Hz(2/3) over a 6 GHz electrical signal bandwidth. While our digital broadband linearization technique advances state-of-the-art optical links, it can also be applied to other nonlinear dynamic systems.

  16. Optical wireless communication using positive real-valued orthogonal frequency-division multiplexing and optical beamforming

    Science.gov (United States)

    Kim, Sung-Man; Kwon, Ki-Keun

    2017-07-01

    The relatively unsatisfactory performance of optical wireless communication (OWC) with respect to WiFi and millimeter-wave communications has formed a key issue preventing its commercialization. We experimentally demonstrate an OWC technology using a combination of positive real-valued orthogonal frequency-division multiplexing (OFDM) and optical beamforming (OB). Due to the intensity-modulation and direct-detection aspects of OWC systems, a positive real-valued OFDM signal can be suitably utilized to maximize the OWC data rate. Further, the OB technique, which can focus laser light on a desired target, can be utilized to increase the OWC data rate and transmission distance. Our experimental results show that the received optical signal power and electrical signal increase by up to 42 and 25 dB, respectively. Further, the data rate increases by a factor of 200 with OB over the conventional approach.

  17. Dust Effect on The Performance of Optical Wireless Communication System

    Directory of Open Access Journals (Sweden)

    Fadel Abdul-Zahra Murad

    2017-11-01

    Full Text Available In this paper wireless optical communication system (FSO is designed through the use of software (Optisystem . The paper also study  the effect of atmospheric dust on the performance of communication system (FSO, the effect of dust concentration on the visibility by taking a different concentrations of dust (9, 20, 40, 60, 80 100, 120 gm / month / m2 . The effect of the visibility on the attenuation of dust concentration on each of these concentrations , and calculate attenuation of dust for the  wavelengths  (784 nm, 1550 nm. The Paper also deals with effect of the transmitted laser  power on the transmitter range (propagation distance where five different values of transmitted laser power (10mw, 20mw, 30mw, 40mw, 50mw are taken  and the study calculates the maximum transmitter range of  each value of the transmitted power under the influence of attenuation atmospheric dust concentrations for each concentration of dust used and also for the two wavelengths (1550nm, 784nm.

  18. Wireless link and microelectronics design for retinal prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wentai [Univ. of California, Santa Cruz, CA (United States)

    2012-02-29

    This project focuses on delivering power and data to the artificial retinal implant inside the eye and the implant microstimulator electronics which delivers the current pulses to stimulate the retinal layer to elicit visual perception. Since the use of invasive means such as tethering wires to transmit power and data results in discomfort to the patients which could eventually cause infection due to the abrasion caused by the wire and contact of the internals of the eye to the external environment, a completely wireless approach is used to transfer both power and data. Power is required inside the eye for the microelectronic implant which uses a dual voltage supply scheme (positive and negative) to deliver biphasic (anodic and cathodic) current pulses. Data in the form of digital bits from the data transmitter external to the eye, carries information about the amplitude, phase width, interphase delay, stimulation sequence for each implant electrode. The data receiver unit decodes the digital stream and the microstimulator unit generates the appropriate current stimuli. Since the external unit consisting of the power transmitter can experience coupling a variation with the power receiver due to the patient’s movements, a closed loop approach is used which varies the transmitted power dynamically to automatically compensate for such movements. This report presents the salient features of this research activities and results.

  19. Spectral and spatial characterization of perfluorinated graded-index polymer optical fibers for the distribution of optical wireless communication cells.

    Science.gov (United States)

    Hajjar, Hani Al; Montero, David S; Lallana, Pedro C; Vázquez, Carmen; Fracasso, Bruno

    2015-02-10

    In this paper, the characterization of a perfluorinated graded-index polymer optical fiber (PF-GIPOF) for a high-bitrate indoor optical wireless system is reported. PF-GIPOF is used here to interconnect different optical wireless access points that distribute optical free-space high-bitrate wireless communication cells. The PF-GIPOF channel is first studied in terms of transmission attenuation and frequency response and, in a second step, the spatial power profile distribution at the fiber output is analyzed. Both characterizations are performed under varying restricted mode launch conditions, enabling us to assess the transmission channel performance subject to potential connectorization errors within an environment where the end users may intervene by themselves on the home network infrastructure.

  20. Capacity and Shaping in Coherent Fiber-Optic Links

    DEFF Research Database (Denmark)

    Estaran Tolosa, Jose Manuel; Zibar, Darko; Tafur Monroy, Idelfonso

    2014-01-01

    Over view of the concepts and latest progress of capacity and constellation shaping incoherent optical links.......Over view of the concepts and latest progress of capacity and constellation shaping incoherent optical links....

  1. Microwave Photonics Techniques Supporting Flexible Wireless Communications Links

    DEFF Research Database (Denmark)

    Rommel, Simon; Cavalcante, Lucas Costa Pereira; Vegas Olmos, Juan José

    constrains. Microwave photonic techniques support a number of key functionalities required to satisfy above-mentioned demands. We will review, in particular, experimental realizations of a number of functionalities such as mmw generation, detection, optical fiber transport and multi-Gigabit data transmission...

  2. Optical links in handheld multimedia devices

    Science.gov (United States)

    van Geffen, S.; Duis, J.; Miller, R.

    2008-04-01

    Ever emerging applications in handheld multimedia devices such as mobile phones, laptop computers, portable video games and digital cameras requiring increased screen resolutions are driving higher aggregate bitrates between host processor and display(s) enabling services such as mobile video conferencing, video on demand and TV broadcasting. Larger displays and smaller phones require complex mechanical 3D hinge configurations striving to combine maximum functionality with compact building volumes. Conventional galvanic interconnections such as Micro-Coax and FPC carrying parallel digital data between host processor and display module may produce Electromagnetic Interference (EMI) and bandwidth limitations caused by small cable size and tight cable bends. To reduce the number of signals through a hinge, the mobile phone industry, organized in the MIPI (Mobile Industry Processor Interface) alliance, is currently defining an electrical interface transmitting serialized digital data at speeds >1Gbps. This interface allows for electrical or optical interconnects. Above 1Gbps optical links may offer a cost effective alternative because of their flexibility, increased bandwidth and immunity to EMI. This paper describes the development of optical links for handheld communication devices. A cable assembly based on a special Plastic Optical Fiber (POF) selected for its mechanical durability is terminated with a small form factor molded lens assembly which interfaces between an 850nm VCSEL transmitter and a receiving device on the printed circuit board of the display module. A statistical approach based on a Lean Design For Six Sigma (LDFSS) roadmap for new product development tries to find an optimum link definition which will be robust and low cost meeting the power consumption requirements appropriate for battery operated systems.

  3. Wireless and wireline service convergence in next generation optical access networks - the FP7 WISCON project

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Pang, Xiaodan; Lebedev, Alexander

    2014-01-01

    . In this paper, we will present the Marie Curie Framework Program 7 project “Wireless and wireline service convergence in next generation optical access networks” (WISCON), which focuses on the conception and study of novel architectures for wavelength-division-multiplexing (WDM) optical multi-modulation format...... radio-over-fiber (RoF) systems; this is a promising solution to implement broadband seamless wireless -wireline access networks. This project successfully concluded in autumn 2013, and is being follow up by another Marie Curie project entitled “flexible edge nodes for dynamic optical interconnection...

  4. UHD Video Transmission over Bi-Directional Underwater Wireless Optical Communication

    KAUST Repository

    Al-Halafi, Abdullah

    2018-04-02

    In this paper, we experimentally demonstrate for the first time a bi-directional underwater wireless optical communication system that is capable of transmitting an ultra high definition real-time video using a downlink channel while simultaneously receiving the feedback messages on the uplink channel. The links extend up to 4.5 m using QPSK, 16-QAM and 64-QAM modulations. The system is built using software defined platforms connected to TO-9 packaged pigtailed 520 nm directly modulated green laser diode (LD) with 1.2 GHz bandwidth as the optical transmitter for video streaming on the downlink, and an avalanche photodiode (APD) module as the downlink receiver. The uplink channel is connected to another pigtailed 450 nm directly modulated blue LD with 1.2 GHz bandwidth as the optical uplink transmitter for the feedback channel, and to a second APD as the uplink receiver. We perform laboratory experiments on different water types. The measured throughput is 15 Mbps for QPSK, and 30 Mbps for both 16-QAM and 64-QAM. We evaluate the quality of the received live video streams using Peak Signal-to-Noise Ratio and achieve values up to 16 dB for 64-QAM when streaming UHD video in harbor II water and 22 dB in clear ocean.

  5. VillageLink: Wide-Area Wireless Coverage

    CSIR Research Space (South Africa)

    Pejovic, V

    2014-01-01

    Full Text Available beyond simple channel utilization balancing, and uses frequency probing to profile channels according to their propagation properties. We devise VillageLink, a Gibbs sampling-based method that optimizes channel allocation in a distributed manner with a...

  6. Energy Efficient Link Aware Routing with Power Control in Wireless Ad Hoc Networks.

    Science.gov (United States)

    Katiravan, Jeevaa; Sylvia, D; Rao, D Srinivasa

    2015-01-01

    In wireless ad hoc networks, the traditional routing protocols make the route selection based on minimum distance between the nodes and the minimum number of hop counts. Most of the routing decisions do not consider the condition of the network such as link quality and residual energy of the nodes. Also, when a link failure occurs, a route discovery mechanism is initiated which incurs high routing overhead. If the broadcast nature and the spatial diversity of the wireless communication are utilized efficiently it becomes possible to achieve improvement in the performance of the wireless networks. In contrast to the traditional routing scheme which makes use of a predetermined route for packet transmission, such an opportunistic routing scheme defines a predefined forwarding candidate list formed by using single network metrics. In this paper, a protocol is proposed which uses multiple metrics such as residual energy and link quality for route selection and also includes a monitoring mechanism which initiates a route discovery for a poor link, thereby reducing the overhead involved and improving the throughput of the network while maintaining network connectivity. Power control is also implemented not only to save energy but also to improve the network performance. Using simulations, we show the performance improvement attained in the network in terms of packet delivery ratio, routing overhead, and residual energy of the network.

  7. Integration and Analysis of Neighbor Discovery and Link Quality Estimation in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Marjan Radi

    2014-01-01

    Full Text Available Network connectivity and link quality information are the fundamental requirements of wireless sensor network protocols to perform their desired functionality. Most of the existing discovery protocols have only focused on the neighbor discovery problem, while a few number of them provide an integrated neighbor search and link estimation. As these protocols require a careful parameter adjustment before network deployment, they cannot provide scalable and accurate network initialization in large-scale dense wireless sensor networks with random topology. Furthermore, performance of these protocols has not entirely been evaluated yet. In this paper, we perform a comprehensive simulation study on the efficiency of employing adaptive protocols compared to the existing nonadaptive protocols for initializing sensor networks with random topology. In this regard, we propose adaptive network initialization protocols which integrate the initial neighbor discovery with link quality estimation process to initialize large-scale dense wireless sensor networks without requiring any parameter adjustment before network deployment. To the best of our knowledge, this work is the first attempt to provide a detailed simulation study on the performance of integrated neighbor discovery and link quality estimation protocols for initializing sensor networks. This study can help system designers to determine the most appropriate approach for different applications.

  8. Modeling of optical wireless scattering communication channels over broad spectra.

    Science.gov (United States)

    Liu, Weihao; Zou, Difan; Xu, Zhengyuan

    2015-03-01

    The air molecules and suspended aerosols help to build non-line-of-sight (NLOS) optical scattering communication links using carriers from near infrared to visible light and ultraviolet bands. This paper proposes channel models over such broad spectra. Wavelength dependent Rayleigh and Mie scattering and absorption coefficients of particles are analytically obtained first. They are applied to the ray tracing based Monte Carlo method, which models the photon scattering angle from the scatterer and propagation distance between two consecutive scatterers. Communication link path loss is studied under different operation conditions, including visibility, particle density, wavelength, and communication range. It is observed that optimum communication performances exist across the wavelength under specific atmospheric conditions. Infrared, visible light and ultraviolet bands show their respective features as conditions vary.

  9. Outage analysis of relay-assisted underwater wireless optical communication systems

    Science.gov (United States)

    Tabeshnezhad, Azadeh; Pourmina, Mohammad Ali

    2017-12-01

    In this paper, we theoretically evaluate the outage probabilities of underwater wireless optical communication (UWOC) systems. Our derivations are general as the channel model under consideration takes into account all of the channel degrading effects, namely absorption, scattering, and turbulence-induced fading. We numerically show that the UWOC systems, due to the severe channel impairments, cannot typically support longer link ranges than 100 m. Therefore, in this paper, in order to increase the transmission reliability and hence extend the viable communication range of UWOC systems, we apply decode-and-forward (DF) relay-assisted communications either in the form of multi-hop transmission, where multiple intermediate relays are serially employed between the source and destination, or parallel relaying in which multiple DF relays are distributed among the source-to-destination path to cooperate in the end-to-end transmission. Our numerical results reveal that multi-hop transmission, owing to the distance-dependency of all of the channel degrading effects, can tremendously improve the end-to-end outage probability and increase the accessible link ranges to hundreds of meter. For example, a dual-hop transmission in a 45 m coastal water link can provide up to 41 dB performance improvement at the outage probability of 10-9.

  10. Adaptive Bit Rate Video Streaming Through an RF/Free Space Optical Laser Link

    Directory of Open Access Journals (Sweden)

    A. Akbulut

    2010-06-01

    Full Text Available This paper presents a channel-adaptive video streaming scheme which adjusts video bit rate according to channel conditions and transmits video through a hybrid RF/free space optical (FSO laser communication system. The design criteria of the FSO link for video transmission to 2.9 km distance have been given and adaptive bit rate video streaming according to the varying channel state over this link has been studied. It has been shown that the proposed structure is suitable for uninterrupted transmission of videos over the hybrid wireless network with reduced packet delays and losses even when the received power is decreased due to weather conditions.

  11. Interconnecting wearable devices with nano-biosensing implants through optical wireless communications

    Science.gov (United States)

    Johari, Pedram; Pandey, Honey; Jornet, Josep M.

    2018-02-01

    Major advancements in the fields of electronics, photonics and wireless communication have enabled the development of compact wearable devices, with applications in diverse domains such as fitness, wellness and medicine. In parallel, nanotechnology is enabling the development of miniature sensors that can detect events at the nanoscale with unprecedented accuracy. On this matter, in vivo implantable Surface Plasmon Resonance (SPR) nanosensors have been proposed to analyze circulating biomarkers in body fluids for the early diagnosis of a myriad of diseases, ranging from cardiovascular disorders to different types of cancer. In light of these results, in this paper, an architecture is proposed to bridge the gap between these two apparently disjoint paradigms, namely, the commercial wearable devices and the advanced nano-biosensing technologies. More specifically, this paper thoroughly assesses the feasibility of the wireless optical intercommunications of an SPR-based nanoplasmonic biochip -implanted subcutaneously in the wrist-, with a nanophotonic wearable smart band which is integrated by an array of nano-lasers and photon-detectors for distributed excitation and measurement of the nanoplasmonic biochip. This is done through a link budget analysis which captures the peculiarities of the intra-body optical channel at (sub) cellular level, the strength of the SPR nanosensor reflection, as well as the capabilities of the nanolasers (emission power, spectrum) and the nano photon-detectors (sensitivity and noise equivalent power). The proposed analysis guides the development of practical communication designs between the wearable devices and nano-biosensing implants, which paves the way through early-stage diagnosis of severe diseases.

  12. Experimental demonstration of a novel indoor optical wireless localization system for high-speed personal area networks.

    Science.gov (United States)

    Wang, Ke; Nirmalathas, Ampalavanapillai; Lim, Christina; Skafidas, Efstratios

    2015-04-01

    In this Letter, we propose a novel indoor localization system based on optical wireless technology. By using the same architecture as the high-speed full-duplex indoor optical wireless communication system, the "search and scan" process, and the added transmission power and beam footprint information in the "search and scan" message, indoor localization functionality is achieved. Proof-of-concept experiments are carried out, and results show that an average error of optical wireless communication system, high-speed indoor wireless personal area networks can be achieved.

  13. A study of the impact of frequency selectivity on link adaptive wireless LAN systems

    OpenAIRE

    Armour, SMD; Doufexi, A; Nix, AR; Bull, DR

    2002-01-01

    Wireless local area networks (WLANs) supporting broadband multimedia communication are being developed and standardized around the world. The HIPERLAN/2, 802.11a and HiSWANa standards provide channel adaptive data rates between 6 and 54 Mbps in the 5GHz radio band. The link adaptation mechanism is not specified in the standards. In this paper the performance of the HIPERLAN/2 system is evaluated in terms of throughput in a range of test channels with different degrees of frequency selectivity...

  14. Millimeter Wave Hybrid Photonic Wireless Links for High-Speed Wireless Access and Mobile Fronthaul

    DEFF Research Database (Denmark)

    Rommel, Simon

    , demonstrating their potential and pushing their implementation beyond the state of the art. While touching upon a multitude of aspects, the contributions can mostly be classified in three larger groups: first, the demonstration of mmw radio-over-fiber (rof) links in various configurations of reduced complexity...

  15. A secure wireless mobile-to-server link

    Science.gov (United States)

    Kumar, Abhinav; Akopian, David; Agaian, Sos; Creutzburg, Reiner

    2009-02-01

    Modern mobile devices are some of the most technologically advanced devices that people use on a daily basis and the current trends indicate continuous growth in mobile phone applications. Nowadays phones are equipped with cameras that can capture still images and video, they are equipped with software that can read, convert, manipulate, communicate and save multimedia in multiple formats. This tremendous progress increased the volumes of communicated sensitive information which should be protected against unauthorized access. This paper discusses two general approaches for data protection, steganography and cryptography, and demonstrates how to integrate such algorithms with a mobile-toserver link being used by many applications.

  16. A Wearable Wireless Energy Link for Thin-Film Batteries Charging

    Directory of Open Access Journals (Sweden)

    Giuseppina Monti

    2016-01-01

    Full Text Available A wireless charger for low capacity thin-film batteries is presented. The proposed device consists of a nonradiative wireless resonant energy link and a power management unit. Experimental data referring to a prototype operating in the ISM band centered at 434 MHz are presented and discussed. In more detail, in order to facilitate the integration into wearable accessories (such as handbags or suitcases, the prototype of the wireless energy link was implemented by exploiting a magnetic coupling between two planar resonators fabricated by using a conductive fabric on a layer of leather. From experimental data, it is demonstrated that, at 434 MHz, the RF-to-RF power transfer efficiency of the link is approximately 69.3%. As for the performance of the system as a whole, when an RF power of 7.5 dBm is provided at the input port, a total efficiency of about 29.7% is obtained. Finally, experiments performed for calculating the charging time for a low capacity thin-film battery demonstrated that, for RF input power higher than 6 dBm, the time necessary for recharging the battery is lower than 50 minutes.

  17. Impact of background light induced shot noise in high-speed full-duplex indoor optical wireless communication systems.

    Science.gov (United States)

    Wang, Ke; Nirmalathas, Ampalavanapillai; Lim, Christina; Skafidas, Efstratios

    2011-10-24

    The use of infrared radiation to provide high speed indoor wireless communication has attracted considerable attention for over a decade. In previous studies we proposed a novel full-duplex indoor optical wireless communication system with high-speed data transmission and limited mobility can be provided to users. When it is incorporated with localization function, gigabit mobile communication can be provided over the entire room. In this paper we theoretically analyze the limiting factor of our proposed system - background light induced shot noise. A theoretical model that allows the receiver sensitivity and the corresponding power penalty is proposed and the model is validated by experiments. Experimental results show that for both down-link and up-link transmission the background light will result in several dB power penalty and it is more dominant in lower speed links. As the bit rate increases, the preamplifier induced noise becomes larger and eventually dominates the noise process. © 2011 Optical Society of America

  18. A cost-effective WDM-PON architecture simultaneously supporting wired, wireless and optical VPN services

    Science.gov (United States)

    Wu, Yanzhi; Ye, Tong; Zhang, Liang; Hu, Xiaofeng; Li, Xinwan; Su, Yikai

    2011-03-01

    It is believed that next-generation passive optical networks (PONs) are required to provide flexible and various services to users in a cost-effective way. To address this issue, for the first time, this paper proposes and demonstrates a novel wavelength-division-multiplexed PON (WDM-PON) architecture to simultaneously support three types of services: 1) wireless access traffic, 2) optical virtual passive network (VPN) communications, and 3) conventional wired services. In the optical line terminal (OLT), we use two cascaded Mach-Zehnder modulators (MZMs) on each wavelength channel to generate an optical carrier, and produce the wireless and the downstream traffic using the orthogonal modulation technique. In each optical network unit (ONU), the obtained optical carrier is modulated by a single MZM to provide the VPN and upstream communications. Consequently, the light sources in the ONUs are saved and the system cost is reduced. The feasibility of our proposal is experimentally and numerically verified.

  19. An Inductive Link-Based Wireless Power Transfer System for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    M. A. Adeeb

    2012-01-01

    Full Text Available A wireless power transfer system using an inductive link has been demonstrated for implantable sensor applications. The system is composed of two primary blocks: an inductive power transfer unit and a backward data communication unit. The inductive link performs two functions: coupling the required power from a wireless power supply system enabling battery-less, long-term implant operation and providing a backward data transmission path. The backward data communication unit transmits the data to an outside reader using FSK modulation scheme via the inductive link. To demonstrate the operation of the inductive link, a board-level design has been implemented with high link efficiency. Test results from a fabricated sensor system, composed of a hybrid implementation of custom-integrated circuits and board-level discrete components, are presented demonstrating power transmission of 125 mW with a 12.5% power link transmission efficiency. Simultaneous backward data communication involving a digital pulse rate of up to 10 kbps was also observed.

  20. Converged wireline and wireless signal distribution in optical fiber access networks

    DEFF Research Database (Denmark)

    Prince, Kamau

    This thesis presents results obtained during the course of my doctoral studies into the transport of fixed and wireless signaling over a converged otpical access infrastructure. In the formulation, development and assessment of a converged paradigma for multiple-services delivery via optical access...... networking infrastructure, I have demonstrated increased functionalities with existing optical technologies and commercially available optoelectronic devices. I have developed novel systems for extending the range of optical access systems, and have demonstrated the repurposing of standard digital devices...

  1. A novel power and offset allocation method for spatial multiplexing MIMO Systems in optical wireless channels

    KAUST Repository

    Park, Kihong

    2011-12-01

    We consider optical wireless communication which can be utilized for illumination and communication by relying on lighting devices. Due to the limited bandwidth of optical sources, it is challenging to achieve high data rate in optical wireless systems. In order to obtain a multiplexing gain and high spectral efficiency, we design an optical multi-input multi-output (MIMO) system utilizing a singular value decomposition-based spatial multiplexing and adaptive modulation. We note that the conventional allocation method in radio frequency MIMO channels cannot be applied directly to the optical intensity channels. In this paper, we generalize the result of power allocation method in [1] for arbitrary number of transmit and receive antennas in optical wireless MIMO systems. Based on three constraints, namely, the nonnegativity, the aggregate optical power, and the bit error rate requirement, we propose a novel method to allocate the optical power, the offset value, and the modulation size for maximum sum rate. From some selected simulation results, we show that our proposed allocation method gives a better spectral efficiency than the method that allocates the optical power equally for each data stream. © 2011 IEEE.

  2. Optimization of Wireless Optical Communication System Based on Augmented Lagrange Algorithm

    International Nuclear Information System (INIS)

    He Suxiang; Meng Hongchao; Wang Hui; Zhao Yanli

    2011-01-01

    The optimal model for wireless optical communication system with Gaussian pointing loss factor is studied, in which the value of bit error probability (BEP) is prespecified and the optimal system parameters is to be found. For the superiority of augmented Lagrange method, the model considered is solved by using a classical quadratic augmented Lagrange algorithm. The detailed numerical results are reported. Accordingly, the optimal system parameters such as transmitter power, transmitter wavelength, transmitter telescope gain and receiver telescope gain can be established, which provide a scheme for efficient operation of the wireless optical communication system.

  3. Optical wireless communication through fog in the presence of pointing errors.

    Science.gov (United States)

    Kedar, Debbie; Arnon, Shlomi

    2003-08-20

    Terrestrial optical wireless communication (OWC) is emerging as a promising technology, which makes connectivity possible between high-rise buildings and metropolitan and intercity communication infrastructures. A light beam carries the information, which facilitates extremely high data rates. However, strict alignment between the transmitter and the receiver must be maintained at all times, and a pointing error can result in a total severance of the communication link. In addition, the presence of fog and haze in the propagation channel hampers OWC as the small water droplets scatter the propagating light. This causes attenuation due to the resultant spatial, angular, and temporal spread of the light signal. Furthermore, the ensuing low visibility may impede the operation of the tracking and pointing system so that pointing errors occur. We develop a model of light transmission through fogs of different optical densities and types using Monte Carlo simulations. Based on this model, the performance of OWC in fogs is evaluated at different wavelengths. The handicap of a transceiver pointing error is added to the model, and the paradoxically advantageous aspects of the transmission medium are exposed. The concept of a variable field of view receiver for narrow-beam OWC is studied, and the possibility of thus enhancing communication system performance through fog in an inexpensive and simple way is indicated.

  4. Performance of an optical wireless communication system as a function of wavelength.

    Science.gov (United States)

    Manor, Haim; Arnon, Shlomi

    2003-07-20

    Optical wireless communication (OWC) is gaining acceptance in an increasing number of sectors of science and industry, owing to its unique combination of features: extremely high bandwidth, rapid deployment time, license- and tariff-free bandwidth allocation, and low power consumption, weight, and size. However, the major drawback of OWC in terrestrial applications is the threat of downtime caused by adverse weather conditions, such as fog and haze. Several researchers have proposed and developed communication systems that use far-IR radiation to mitigate weather effects. In this study we analyze the performance of a short-distance terrestrial OWC system as a function of wavelength. A mathematical model for OWC link performance is derived. Using this model, we perform a simulation of our system under different weather conditions. From the results of our calculations, the improvement of link availability for 10 microm compared with 0.785-1.55 microm for a distance of 1-km propagation is 0.2% (99.6-99.8%). This modest improvement should be considered relative to the complexity and cost of quantum cascade laser transmitters and far-IR receivers.

  5. Polybinary modulation for bandwidth limited optical links

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Jurado-Navas, Antonio

    2015-01-01

    Optical links using traditional modulation formats are reaching a plateau in terms of capacity, mainly due to bandwidth limitations in the devices employed at the transmitter and receivers. Advanced modulation formats, which boost the spectral efficiency, provide a smooth migration path towards...... effectively increase the available capacity. Advanced modulation formats however require digitalization of the signals and digital signal processing blocks to both generate and recover the data. There is therefore a trade-off in terms of efficiency gain vs. complexity. Poly binary modulation, a generalized...... form of partial response modulation, employs simple codification and filtering at the transmitter to drastically increase the spectral efficiency. At the receiver side, poly binary modulation requires low complexity direct detection and very little digital signal processing. This talk will review...

  6. Reflective analogue optical link operating issues

    CERN Document Server

    Batten, Jeremy

    1996-01-01

    The proposed readout of analogue data from CMS tracker will use an optical fibre link. The choice of transmitter/receiver technology, however, has been the subject of intense research and development by the RD23 collaboration. One solution uses passive devices, multi-quantum well modulators, at the detector front end, and continuous wave driving lasers at the readout back end. This system has been tested at Imperial College. We report on the following: problems of noise associated with multimoded behaviour of a degraded laser; measurements of laser wavelength dependence on both drive current and temperature; and modulator reflectance dependence on laser wavelength. We extrapolate the findings to system issues, highlighting the degree of temperature control required of the driving laser.

  7. Combined single-mode/multimode fiber link supporting simplified in-building 60-GHz gigabit wireless access

    DEFF Research Database (Denmark)

    Pham, Tien Thang; Lebedev, Alexander; Beltrán, Marta

    2012-01-01

    In this paper, we propose and experimentally demonstrate a simple, cost-effective hybrid gigabit fiber-wireless system for in-building wireless access. Simplicity and cost-effectiveness are achieved in all parts of the system by utilizing direct laser modulation, optical frequency up-conversion, ......In this paper, we propose and experimentally demonstrate a simple, cost-effective hybrid gigabit fiber-wireless system for in-building wireless access. Simplicity and cost-effectiveness are achieved in all parts of the system by utilizing direct laser modulation, optical frequency up......-conversion, combined single mode/multimode fiber transmission and envelope detection. Error-free transmission of 2-Gbps data in 60-GHz band over a composite channel including 10-km standard single-mode fiber (SSMF)/1-km multimode fiber (MMF) and 6.5-m air transmission was successfully achieved....

  8. A Pulsed Coding Technique Based on Optical UWB Modulation for High Data Rate Low Power Wireless Implantable Biotelemetry

    Directory of Open Access Journals (Sweden)

    Andrea De Marcellis

    2016-10-01

    Full Text Available This paper reports on a pulsed coding technique based on optical Ultra-wideband (UWB modulation for wireless implantable biotelemetry systems allowing for high data rate link whilst enabling significant power reduction compared to the state-of-the-art. This optical data coding approach is suitable for emerging biomedical applications like transcutaneous neural wireless communication systems. The overall architecture implementing this optical modulation technique employs sub-nanosecond pulsed laser as the data transmitter and small sensitive area photodiode as the data receiver. Moreover, it includes coding and decoding digital systems, biasing and driving analogue circuits for laser pulse generation and photodiode signal conditioning. The complete system has been implemented on Field-Programmable Gate Array (FPGA and prototype Printed Circuit Board (PCB with discrete off-the-shelf components. By inserting a diffuser between the transmitter and the receiver to emulate skin/tissue, the system is capable to achieve a 128 Mbps data rate with a bit error rate less than 10−9 and an estimated total power consumption of about 5 mW corresponding to a power efficiency of 35.9 pJ/bit. These results could allow, for example, the transmission of an 800-channel neural recording interface sampled at 16 kHz with 10-bit resolution.

  9. A closed-form solution of the bit-error rate for optical wireless communication systems over atmospheric turbulence channels.

    Science.gov (United States)

    Dang, Anhong

    2011-02-14

    Atmospheric turbulence is a major limiting factor in an optical wireless communication (OWC) link. The turbulence distorts the phase of the propagating optical fields and limits the focusing capabilities of the telescope antennas. Hence, a detector array is required to capture the widespread signal energy in the focal-plane. This paper addresses the bit-error rate (BER) performance of optical wireless communication (OWC) systems employing a detector array in the presence of turbulence. Here, considering the gamma-gamma turbulence model, we propose a blind estimation scheme that provides the closed-form expression of the BER by exploiting the information of the data output of each pixel, which is based on the singular value decomposition of the sample matrix of the received signals after the code-matched filter. Instead of assuming spatially white additive noise, we consider the case where the noise spatial covariance matrix is unknown. The new method can be applied to either the single transmitter or the multi-transmitter cases. Simulation results for different Rytov variances are presented, which conform closely to the results of the proposed model.

  10. Real-time 2.5  Gbit/s spatial circuit switching on W-band wireless links

    DEFF Research Database (Denmark)

    Rodríguez, Sebastián; Morales Vicente, Alvaro; Gallardo, Omar

    2017-01-01

    A spatial circuit switching system based on a beam steering application for W-band wireless links is proposed and experimentally demonstrated. The system enables two simultaneous transmissions of a 2.5 Gbit∕s data signal over a carrier of 81 GHz, while allowing the receiver to dynamically switch ...... between them. The performance of the system is tested with the real-time measurements of the BER, achieving values below the FEC limit for 7% of overhead and serving to prove the viability of wireless spatial circuit switching in the next generation of wireless access networks....

  11. Low-Cost, High-Performance Analog Optical Links

    National Research Council Canada - National Science Library

    Prince, Joelle; Burns, William; Ackerman, Edward; Cox, Charles; Roussell, Harold; Makrides, Frank; Regan, Michael

    2006-01-01

    ... of 0.5 W/A by forcing the link's input RF signal to feed a series-connected succession of multiple laser junctions whose optical outputs are collected in parallel to illuminate the link's single photodetector...

  12. 2.3 Gbit/s underwater wireless optical communications using directly modulated 520 nm laser diode.

    Science.gov (United States)

    Oubei, Hassan Makine; Li, Changping; Park, Ki-Hong; Ng, Tien Khee; Alouini, Mohamed-Slim; Ooi, Boon S

    2015-08-10

    We experimentally demonstrate a record high-speed underwater wireless optical communication (UWOC) over 7 m distance using on-off keying non-return-to-zero (OOK-NRZ) modulation scheme. The communication link uses a commercial TO-9 packaged pigtailed 520 nm laser diode (LD) with 1.2 GHz bandwidth as the optical transmitter and an avalanche photodiode (APD) module as the receiver. At 2.3 Gbit/s transmission, the measured bit error rate of the received data is 2.23×10(-4), well below the forward error correction (FEC) threshold of 2×10(-3) required for error-free operation. The high bandwidth of the LD coupled with high sensitivity APD and optimized operating conditions is the key enabling factor in obtaining high bit rate transmission in our proposed system. To the best of our knowledge, this result presents the highest data rate ever achieved in UWOC systems thus far.

  13. 2.3 Gbit/s underwater wireless optical communications using directly modulated 520 nm laser diode

    KAUST Repository

    Oubei, Hassan M.

    2015-07-30

    We experimentally demonstrate a record high-speed underwater wireless optical communication (UWOC) over 7 m distance using on-off keying non-return-to-zero (OOK-NRZ) modulation scheme. The communication link uses a commercial TO-9 packaged pigtailed 520 nm laser diode (LD) with 1.2 GHz bandwidth as the optical transmitter and an avalanche photodiode (APD) module as the receiver. At 2.3 Gbit/s transmission, the measured bit error rate of the received data is 2.23×10−4, well below the forward error correction (FEC) threshold of 2×10−3 required for error-free operation. The high bandwidth of the LD coupled with high sensitivity APD and optimized operating conditions is the key enabling factor in obtaining high bit rate transmission in our proposed system. To the best of our knowledge, this result presents the highest data rate ever achieved in UWOC systems thus far.

  14. Congestion control in wireless links based on selective delivery of erroneous packets

    DEFF Research Database (Denmark)

    Korhonen, Jari; Perkis, Andrew; Reiter, Ulrich

    2011-01-01

    Traditionally, congestion control in packet networks is performed by reducing the transmission rate when congestion is detected, in order to cut down the traffic that overwhelms the capacity of the network. However, if the bottleneck is a wireless link, congestion is often cumulated because...... of bit errors appearing in the packet payload. In this paper, we study a congestion control mechanism for streaming applications that combines traditional congestion control with selective link layer partial checksumming allowing bit errors in the less sensitive parts of data. We have compared...... of retransmissions derived from bit errors. In this case, it might be beneficial to allow delivery of partly corrupted packets up to the application layer instead of reducing the transmission rate. This would decrease the number of retransmissions in the link layer and therefore relieve congestion, but at the cost...

  15. Multi-gigabit/s underwater optical communication link using orbital angular momentum multiplexing.

    Science.gov (United States)

    Baghdady, Joshua; Miller, Keith; Morgan, Kaitlyn; Byrd, Matthew; Osler, Sean; Ragusa, Robert; Li, Wenzhe; Cochenour, Brandon M; Johnson, Eric G

    2016-05-02

    In this work we experimentally demonstrated an underwater wireless optical communications (UWOC) link over a 2.96 m distance with two 445-nm fiber-pigtailed laser diodes employing Orbital Angular Momentum (OAM) to allow for spatial multiplexing. Using an on-off keying, non-return-to-zero (OOK-NRZ) modulation scheme, a data rate of 3 Gbit/s was achieved in water with an attenuation coefficient of 0.4128 m-1 at an average bit error rate (BER) of 2.073 × 10-4, well beneath the forward error correction (FEC) threshold.

  16. Seamless Translation of Optical Fiber PolMux-OFDM into a 2x2 MIMO Wireless Transmission Enabled by Digital Training-Based Fiber-Wireless Channel Estimation

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Zhao, Ying; Deng, Lei

    2011-01-01

    We propose and demonstrate a 2 × 2 multiple-input multiple-output (MIMO) wireless over fiber transmission system. Seamless translation of two orthogonal frequency division multiplexing (OFDM) signals on dual optical polarization states into wireless MIMO transmission at 795.5 Mbit/s net data rate...... is enabled by using digital training-based channel estimation. A net spectral efficiency of 2.55 bit/s/Hz is achieved....

  17. A 15-meter Multi-Gigabit W-band Bidirectional Wireless Bridge in Fiber-Optic Access Networks

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Vegas Olmos, Juan José; Lebedev, Alexander

    2013-01-01

    . The down-converted signal is re-modulated on to the lightwave and transmit further through the fiber-optic system. In the uplink, both up-and down-conversion are performed by electrical means. Furthermore, we investigate both passive and active wireless transmitters in this work for both downlink...... and uplink transmissions. With an active wireless transmitter, up to 15 meters wireless transmission is successfully achieved with a BER below the 7% FEC limit in the downlink....

  18. Experimental Comparison of Routing Protocols for Wireless Sensors Networks: Routing Overhead and Asymmetric Links

    OpenAIRE

    Audéoud , Henry-Joseph; Heusse , Martin

    2017-01-01

    International audience; RPL (the IETF Routing Protocol for Low-Power and Lossy Networks) and LRP (Lightweight Routing Protocol) have in common to build a collection tree (or, more precisely, a DODAG) and “downward” host routes in the wireless sensor network. Additionally, the objective of LRP is to keep control overhead as low as possible. To substantiate this claim, we compare RPL and LRP using 40 nodes of the IoT-LAB testbed — and the results are telling.We then introduce asymmetric links, ...

  19. Truncated power control for improving TCP/IP performance over CDMA wireless links

    DEFF Research Database (Denmark)

    Cianca, Ernestina; Prasad, Ramjee; De Sanctis, Mauro

    2005-01-01

    The issue of the performance degradation of transmission control protocol/Internet Protocol (TCP/IP) over wireless links due to the presence of noncongestion-related packet losses has been addressed with a physical layer approach. The effectiveness of automatic repeat request techniques in enhanc...... strategy is very effective in improving the end-to-end throughput of a TCP connection. Moreover, these improvements are higher when the traffic is more bursty, like in typical Internet data applications such as e-mail and web surfing....

  20. 0.4 THz Photonic-Wireless Link With 106 Gb/s Single Channel Bitrate

    DEFF Research Database (Denmark)

    Jia, Shi; Pang, Xiaodan; Ozolins, Oskars

    2018-01-01

    THz channel is enabled by combining spectrally efficient modulation format, ultrabroadband THz transceiver and advanced digital signal processing routine. Besides that, our demonstration from system-wide implementation viewpoint also features high transmission stability, and hence shows its great......, we experimentally demonstrate a single channel 0.4 THz photonic-wireless link achieving a net data rate of beyond 100 Gb/s by using a single pair of THz emitter and receiver, without employing any spatial/frequency division multiplexing techniques. The high throughput up to 106 Gb/s within a single...

  1. Fiber-wireless links supporting high-capacity W-band channels

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

    2013-01-01

    , is seeding the need to use bands located at the millimeter-wave region (30-300 GHz), mainly because of its inherent broadband nature. In our lab, we have conducted extensive research on high-speed photonic-wireless links in the V-band (50-75GHz) and the W-band (75-110GHz). In this paper, we will present our...... latest findings and experimental results on the W-band, specifically on its 81-86GHz sub-band. These include photonic generation of millimeter-wave carriers and transmission performance of broadband signals on different types of fibers and span lengths....

  2. Effects of atmospheric turbulence and building sway on optical wireless-communication systems.

    Science.gov (United States)

    Arnon, Shlomi

    2003-01-15

    Urban optical wireless communication (UOWC) systems are considered a last-mile technology. UOWC systems use the atmosphere as a propagation medium. To provide a line of sight the transceivers are placed on high-rise building. However, dynamic wind loads, thermal expansion, and weak earthquakes cause buildings to sway. These sways distort the alignment between transmitter and receiver, causing pointing errors, the outcome of which is fading of the received signal. Furthermore, atmospheric turbulence causes fluctuations in both the intensity and the phase of the received signal, resulting in impaired link performance. A bit-error probability (BEP) model is developed that takes into account both building sway and turbulence-induced log amplitude fluctuations (i.e., fading of signal intensity) in the regime in which the receiver aperture, D0, is smaller than the turbulence coherence diameter, d0. It is assumed that the receiver has knowledge about the marginal statistics of the signal fading and the instantaneous signal-fading state.

  3. Enhancing the decoding performance of optical wireless communication systems using receiver-side predistortion.

    Science.gov (United States)

    Wang, Qi; Wang, Zhaocheng; Chen, Sheng; Hanzo, Lajos

    2013-12-16

    White light emitting diodes (LEDs) have been widely utilized for illumination owing to their desired properties of inherent bright output, high efficiency, low power consumption and long life-time. They are also increasingly applied in optical wireless communications for realizing high data rate transmission. This paper presents an improved scheme relying on the insertion of a simple predistortion module before the decoder at the receiver of optical wireless communication systems that use white LEDs. The proposed predistortion scheme exploits the inherent nature of mixing the three unequal optical-power primary colours in generating white light to enhance the system's performance. Specifically, we design this predistortion module by minimizing the upper bound of the error probability in conjunction with a soft-decision decoder. Our simulation results demonstrate that the detection performance is considerably improved with the aid of the proposed predistortion module.

  4. On the Performance Analysis of Free-Space Optical Links under Generalized Turbulence and Misalignment Models

    KAUST Repository

    AlQuwaiee, Hessa

    2016-11-01

    One of the potential solutions to the radio frequency (RF) spectrum scarcity problem is optical wireless communications (OWC), which utilizes the unlicensed optical spectrum. Long-range outdoor OWC are usually referred to in the literature as free-space optical (FSO) communications. Unlike RF systems, FSO is immune to interference and multi-path fading. Also, the deployment of FSO systems is flexible and much faster than optical fibers. These attractive features make FSO applicable for broadband wireless transmission such as optical fiber backup, metropolitan area network, and last mile access. Although FSO communication is a promising technology, it is negatively affected by two physical phenomenon, namely, scintillation due to atmospheric turbulence and pointing errors. These two critical issues have prompted intensive research in the last decade. To quantify the effect of these two factors on FSO system performance, we need effective mathematical models. In this work, we propose and study a generalized pointing error model based on the Beckmann distribution. Then, we aim to generalize the FSO channel model to span all turbulence conditions from weak to strong while taking pointing errors into consideration. Since scintillation in FSO is analogous to the fading phenomena in RF, diversity has been proposed too to overcome the effect of irradiance fluctuations. Thus, several combining techniques of not necessarily independent dual-branch free-space optical links were investigated over both weak and strong turbulence channels in the presence of pointing errors. On another front, improving the performance, enhancing the capacity and reducing the delay of the communication link has been the motivation of any newly developed schemes, especially for backhauling. Recently, there has been a growing interest in practical systems to integrate RF and FSO technologies to solve the last mile bottleneck. As such, we also study in this thesis asymmetric an RF-FSO dual-hop relay

  5. Distributed and Cooperative Link Scheduling for Large-Scale Multihop Wireless Networks

    Directory of Open Access Journals (Sweden)

    Ananthram Swami

    2007-12-01

    Full Text Available A distributed and cooperative link-scheduling (DCLS algorithm is introduced for large-scale multihop wireless networks. With this algorithm, each and every active link in the network cooperatively calibrates its environment and converges to a desired link schedule for data transmissions within a time frame of multiple slots. This schedule is such that the entire network is partitioned into a set of interleaved subnetworks, where each subnetwork consists of concurrent cochannel links that are properly separated from each other. The desired spacing in each subnetwork can be controlled by a tuning parameter and the number of time slots specified for each frame. Following the DCLS algorithm, a distributed and cooperative power control (DCPC algorithm can be applied to each subnetwork to ensure a desired data rate for each link with minimum network transmission power. As shown consistently by simulations, the DCLS algorithm along with a DCPC algorithm yields significant power savings. The power savings also imply an increased feasible region of averaged link data rates for the entire network.

  6. MIMO channel measurements using optical links on small mobile terminals

    DEFF Research Database (Denmark)

    Yanakiev, Boyan; Nielsen, Jesper Ødum; Pedersen, Gert Frølund

    2010-01-01

    This paper looks at a novel measurement device for propagation channel measurements using a fiber optic link. Although the idea of using optical links is not new, most of the developments in the area are either too big [5], short range [6] or suitable for anechoic chamber only [7]. The device pre...

  7. Protection of Video Packets over a Wireless Rayleigh Fading Link: FEC versus ARQ

    Directory of Open Access Journals (Sweden)

    Marc Moeneclaey

    2008-07-01

    Full Text Available Video content can be provided to an end user by transmitting video data as a sequence of internet protocol (IP packets over the network. When the network contains a wireless link, packet erasures occur because of occasional deep fades. In order to maintain a sufficient video quality at the end user, video packets must be protected against erasures by means of a suitable form of error control. In this contribution, we investigate two types of error control: (1 forward error correction (FEC, which involves the transmission of parity packets that enables recovery of a limited number of erased video packets, and (2 the use of an automatic repeat request (ARQ protocol, where the receiver requests the retransmission of video packets that have been erased. We point out that FEC and ARQ considerably reduce the probability of unrecoverable packet loss, because both error control techniques provide a diversity gain, as compared to the case where no protection against erasures is applied. We derive a simple analytical expression for the diversity gain resulting from FEC or ARQ, in terms of the channel coherence time, the allowable latency, and (for FEC the allowable overhead or (for ARQ the time interval between (retransmissions of copies of a same packet. In the case of HDTV transmission over a 60 GHz indoor wireless link, ARQ happens to outperform FEC.

  8. Truncated power control for improving TCP/IP performance over CDMA wireless links

    DEFF Research Database (Denmark)

    Cianca, Ernestina; Prasad, Ramjee; De Sanctis, Mauro

    2005-01-01

    The issue of the performance degradation of transmission control protocol/Internet Protocol (TCP/IP) over wireless links due to the presence of noncongestion-related packet losses has been addressed with a physical layer approach. The effectiveness of automatic repeat request techniques in enhanc......The issue of the performance degradation of transmission control protocol/Internet Protocol (TCP/IP) over wireless links due to the presence of noncongestion-related packet losses has been addressed with a physical layer approach. The effectiveness of automatic repeat request techniques...... in enhancing TCP/IP performance depends on the tradeoff between frame transmission delay and residual errors after retransmissions. The paper shows how a truncated power control can be effectively applied to improve that tradeoff so that a higher transmission reliability is provided without increasing...... strategy is very effective in improving the end-to-end throughput of a TCP connection. Moreover, these improvements are higher when the traffic is more bursty, like in typical Internet data applications such as e-mail and web surfing....

  9. Wireless, Web-Based Interactive Control of Optical Coherence Tomography with Mobile Devices.

    Science.gov (United States)

    Mehta, Rajvi; Nankivil, Derek; Zielinski, David J; Waterman, Gar; Keller, Brenton; Limkakeng, Alexander T; Kopper, Regis; Izatt, Joseph A; Kuo, Anthony N

    2017-01-01

    Optical coherence tomography (OCT) is widely used in ophthalmology clinics and has potential for more general medical settings and remote diagnostics. In anticipation of remote applications, we developed wireless interactive control of an OCT system using mobile devices. A web-based user interface (WebUI) was developed to interact with a handheld OCT system. The WebUI consisted of key OCT displays and controls ported to a webpage using HTML and JavaScript. Client-server relationships were created between the WebUI and the OCT system computer. The WebUI was accessed on a cellular phone mounted to the handheld OCT probe to wirelessly control the OCT system. Twenty subjects were imaged using the WebUI to assess the system. System latency was measured using different connection types (wireless 802.11n only, wireless to remote virtual private network [VPN], and cellular). Using a cellular phone, the WebUI was successfully used to capture posterior eye OCT images in all subjects. Simultaneous interactivity by a remote user on a laptop was also demonstrated. On average, use of the WebUI added only 58, 95, and 170 ms to the system latency using wireless only, wireless to VPN, and cellular connections, respectively. Qualitatively, operator usage was not affected. Using a WebUI, we demonstrated wireless and remote control of an OCT system with mobile devices. The web and open source software tools used in this project make it possible for any mobile device to potentially control an OCT system through a WebUI. This platform can be a basis for remote, teleophthalmology applications using OCT.

  10. Application of a universal optic data link for radiation measurements

    International Nuclear Information System (INIS)

    Komatsu, T.; Takada, E.

    2002-01-01

    Optic Data Link (ODL) is a device to convert electric and optic signals to each other, which is used for the field of optical communications. We examined the possibility to apply ODLs to radiation measurements. The effect of ODLs on energy and timing resolution has been investigated. From the results, fundamental applicability of ODLs to radiation measurements has been demonstrated. (author)

  11. Numerical models and experiment of air flow in a simulation box for optical wireless communications

    Directory of Open Access Journals (Sweden)

    Latal Jan

    2016-01-01

    Full Text Available In this article, the authors focused on real measurements of mechanical turbulence generated by ventilators in the simulation box for Optical Wireless Communications. The mechanical turbulences disturb the optical beam that propagates along the central axis of the simulation box. The aim of authors is to show the effect of mechanical turbulence on optical beams at different heights in the simulation box. In the Ansys Fluent, we created numerical models which were then compared with real measurements. Authors compared the real and numerical models according to statistical methods.

  12. Digital optical feeder links system for broadband geostationary satellite

    Science.gov (United States)

    Poulenard, Sylvain; Mège, Alexandre; Fuchs, Christian; Perlot, Nicolas; Riedi, Jerome; Perdigues, Josep

    2017-02-01

    An optical link based on a multiplex of wavelengths at 1.55μm is foreseen to be a valuable solution for the feeder link of the next generation of high-throughput geostationary satellite. The main satellite operator specifications for such link are an availability of 99.9% over the year, a capacity around 500Gbit/s and to be bent-pipe. Optical ground station networks connected to Terabit/s terrestrial fibers are proposed. The availability of the optical feeder link is simulated over 5 years based on a state-of-the-art cloud mask data bank and an atmospheric turbulence strength model. Yearly and seasonal optical feeder link availabilities are derived and discussed. On-ground and on-board terminals are designed to be compliant with 10Gbit/s per optical channel data rate taking into account adaptive optic systems to mitigate the impact of atmospheric turbulences on single-mode optical fiber receivers. The forward and return transmission chains, concept and implementation, are described. These are based on a digital transparent on-off keying optical link with digitalization of the DVB-S2 and DVB-RCS signals prior to the transmission, and a forward error correcting code. In addition, the satellite architecture is described taking into account optical and radiofrequency payloads as well as their interfaces.

  13. Delay-aware adaptive sleep mechanism for green wireless-optical broadband access networks

    Science.gov (United States)

    Wang, Ruyan; Liang, Alei; Wu, Dapeng; Wu, Dalei

    2017-07-01

    Wireless-Optical Broadband Access Network (WOBAN) is capacity-high, reliable, flexible, and ubiquitous, as it takes full advantage of the merits from both optical communication and wireless communication technologies. Similar to other access networks, the high energy consumption poses a great challenge for building up WOBANs. To shot this problem, we can make some load-light Optical Network Units (ONUs) sleep to reduce the energy consumption. Such operation, however, causes the increased packet delay. Jointly considering the energy consumption and transmission delay, we propose a delay-aware adaptive sleep mechanism. Specifically, we develop a new analytical method to evaluate the transmission delay and queuing delay over the optical part, instead of adopting M/M/1 queuing model. Meanwhile, we also analyze the access delay and queuing delay of the wireless part. Based on such developed delay models, we mathematically derive ONU's optimal sleep time. In addition, we provide numerous simulation results to show the effectiveness of the proposed mechanism.

  14. A scalable and continuous-upgradable optical wireless and wired convergent access network.

    Science.gov (United States)

    Sung, J Y; Cheng, K T; Chow, C W; Yeh, C H; Pan, C-L

    2014-06-02

    In this work, a scalable and continuous upgradable convergent optical access network is proposed. By using a multi-wavelength coherent comb source and a programmable waveshaper at the central office (CO), optical millimeter-wave (mm-wave) signals of different frequencies (from baseband to > 100 GHz) can be generated. Hence, it provides a scalable and continuous upgradable solution for end-user who needs 60 GHz wireless services now and > 100 GHz wireless services in the future. During the upgrade, user only needs to upgrade their optical networking unit (ONU). A programmable waveshaper is used to select the suitable optical tones with wavelength separation equals to the desired mm-wave frequency; while the CO remains intact. The centralized characteristics of the proposed system can easily add any new service and end-user. The centralized control of the wavelength makes the system more stable. Wired data rate of 17.45 Gb/s and w-band wireless data rate up to 3.36 Gb/s were demonstrated after transmission over 40 km of single-mode fiber (SMF).

  15. Enhanced signaling scheme with admission control in the hybrid optical wireless (HOW) networks

    DEFF Research Database (Denmark)

    Yan, Ying; Yu, Hao; Wessing, Henrik

    2009-01-01

    that it can support stringent Quality of Service (QoS) requirements. In this paper, we describe and evaluate a resource management framework designed for the HOW networks. There are two parts in the resource management framework The first part is the Enhanced MPCP (E-MPCP) scheme aiming at improving signaling......The hybrid optical wireless (HOW) network has been viewed as a promising solution to meet the increasing user bandwidth and mobility demands. Due to the basic differences in the optical and wireless technologies, a challenging problem lies in the Media Access Control (MAC) protocol design so...... dropping probability depend on several factors. These factors include the frame duration, the traffic load and the total number of shared users. The results also highlight that our proposed system achieves significant improvements over the traditional approach in terms of user QoS guarantee and network...

  16. CCM-R: Secure Counter Synchronization for IoT Wireless Link

    DEFF Research Database (Denmark)

    Roy, Upal; Yin, Jiachen; Andersen, Birger

    2016-01-01

    In this paper we propose and evaluate a new version of the CCM mode of operation, CCM-R, which isan extended and alternate version of the original CBC-MAC with Counter Mode(CCM) that was created to address the problem of counter synchronization. While CCM is considered secure when used/implemente......In this paper we propose and evaluate a new version of the CCM mode of operation, CCM-R, which isan extended and alternate version of the original CBC-MAC with Counter Mode(CCM) that was created to address the problem of counter synchronization. While CCM is considered secure when used...... on wireless link. Therefore, in order to solve this problem, we have proposed a solution where we have embedded a secure counter synchronization approach into the original CCM mode of operation. The approach makes it immune to package loss and DoS attacks. The overhead is also kept at a minimum, making...... it suitable for low-power wireless IoT devices....

  17. Frame-Aggregated Link Adaptation Protocol for Next Generation Wireless Local Area Networks

    Directory of Open Access Journals (Sweden)

    Feng Kai-Ten

    2010-01-01

    Full Text Available The performance of wireless networks is affected by channel conditions. Link Adaptation techniques have been proposed to improve the degraded network performance by adjusting the design parameters, for example, the modulation and coding schemes, in order to adapt to the dynamically changing channel conditions. Furthermore, due to the advancement of the IEEE 802.11n standard, the network goodput can be enhanced with the exploitation of its frame aggregation schemes. However, none of the existing link adaption algorithms are designed to consider the feasible number of aggregated frames that should be utilized for channel-changing environments. In this paper, a frame-aggregated link adaptation (FALA protocol is proposed to dynamically adjust system parameters in order to improve the network goodput under varying channel conditions. For the purpose of maximizing network goodput, both the optimal frame payload size and the modulation and coding schemes are jointly obtained according to the signal-to-noise ratio under specific channel conditions. The performance evaluation is conducted and compared to the existing link adaption protocols via simulations. The simulation results show that the proposed FALA protocol can effectively increase the goodput performance compared to other baseline schemes, especially under dynamically-changing environments.

  18. Service Class Resource Management For Green Wireless-Optical Broadband Access NetworksWOBAN

    Directory of Open Access Journals (Sweden)

    SRUTHY.S

    2015-08-01

    Full Text Available Abstract-Broadband access networks have become an essential part of worldwide communication systems because of the exponential growth of broadband services such as video on demand high definition TV internet protocol TV and video conferencing. Exponential growth in the volume of wireless data boosted by the growing popularity of mobile devices such as smartphone and tablets has forced the telecommunication industries to rethink the way networks are currently designed and to focus on the development of high-capacity mobile broadband networks. In response to this challenge researchers have been working toward the development of an integrated wireless optical broadband access network. Two major candidate technologies which are currently known for their high capacity as well as quality of service QoS for multimedia traffic are passive optical networks PON and fourth generation 4G wireless networks. PON is a wired access technology well known for its cost efficiency and high capacity whereas 4G is a wireless broadband access technology which has achieved broad market acceptance because of its ease of deployment ability to offer mobility and its cost efficiency. Integration of PON and 4G technologies in the form of wireless-optical broadband access networks offers advantages such as extension of networks in rural areas support for mobile broadband services and quick deployment of broadband networks. These two technologies however have different design architectures for handling broadband services that require quality of service. For example 4G networks use traffic classification for supporting different QoS demands whereas the PON architecture has no such mechanism to differentiate between types of traffic. These two technologies also differ in their power saving mechanisms. Propose a service class mapping for the integrated PON-4G network which is based on the MG1 queuing model and class-based power saving mechanism which significantly improves the

  19. Bidirectional 3.125 Gbps downstream / 2 Gbps upstream impulse radio ultrawide-band (UWB) over combined fiber and wireless link

    DEFF Research Database (Denmark)

    Jensen, Jesper Bevensee; Gibbon, Timothy Braidwood; Yu, Xianbin

    2010-01-01

    We demonstrate bidirectional fiber and wireless transmission of impulse radio ultra-wideband at 3.125 Gbps downstream and 2 Gbps upstream. After transmission over 50 km fiber and 1.85 m wireless link both signals are recovered without errors.......We demonstrate bidirectional fiber and wireless transmission of impulse radio ultra-wideband at 3.125 Gbps downstream and 2 Gbps upstream. After transmission over 50 km fiber and 1.85 m wireless link both signals are recovered without errors....

  20. Intra-Body Optical Channel Modeling for In Vivo Wireless Nanosensor Networks.

    Science.gov (United States)

    Guo, Hongzhi; Johari, Pedram; Jornet, Josep Miquel; Sun, Zhi

    2016-01-01

    In vivo wireless nanosensor networks (iWNSNs) consist of nanosized communicating devices, which can operate inside the human body in real time. iWNSNs are at the basis of transformative healthcare techniques, ranging from intra-body health-monitoring systems to drug-delivery applications. Plasmonic nanoantennas are expected to enable the communication among nanosensors in the near infrared and optical transmission window. This result motivates the analysis of the phenomena affecting the propagation of such electromagnetic (EM) signals inside the human body. In this paper, a channel model for intra-body optical communication among nanosensors is developed. The total path loss is computed by taking into account the absorption from different types of molecules and the scattering by different types of cells. In particular, first, the impact of a single cell on the propagation of an optical wave is analytically obtained, by modeling a cell as a multi-layer sphere with complex permittivity. Then, the impact of having a large number of cells with different properties arranged in layered tissues is analyzed. The analytical channel model is validated by means of electromagnetic simulations and extensive numerical results are provided to understand the behavior of the intra-body optical wireless channel. The result shows that, at optical frequencies, the scattering loss introduced by cells is much larger than the absorption loss from the medium. This result motivates the utilization of the lower frequencies of the near-infrared window for communication in iWNSNs.

  1. Laser Transmitters for the optical link systems used in CMS

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    In the CMS experiment of the now new flagship LHC optical links will be used for the tracker readout system. One part of this components will be semiconductor laser (~50.000 !!!), named correctly: 1310 nm InGaAsP (DCPBH-MQW) edge-emitting laser. They are foreseen as transmitter in the Tx Hybrid part of the optical link system.

  2. Impact of Radio Link Unreliability on the Connectivity of Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Gorce Jean-Marie

    2007-01-01

    Full Text Available Many works have been devoted to connectivity of ad hoc networks. This is an important feature for wireless sensor networks (WSNs to provide the nodes with the capability of communicating with one or several sinks. In most of these works, radio links are assumed ideal, that is, with no transmission errors. To fulfil this assumption, the reception threshold should be high enough to guarantee that radio links have a low transmission error probability. As a consequence, all unreliable links are dismissed. This approach is suboptimal concerning energy consumption because unreliable links should permit to reduce either the transmission power or the number of active nodes. The aim of this paper is to quantify the contribution of unreliable long hops to an increase of the connectivity of WSNs. In our model, each node is assumed to be connected to each other node in a probabilistic manner. Such a network is modeled as a complete random graph, that is, all edges exist. The instantaneous node degree is then defined as the number of simultaneous valid single-hop receptions of the same message, and finally the mean node degree is computed analytically in both AWGN and block-fading channels. We show the impact on connectivity of two MACs and routing parameters. The first one is the energy detection level such as the one used in carrier sense mechanisms. The second one is the reliability threshold used by the routing layer to select stable links only. Both analytic and simulation results show that using opportunistic protocols is challenging.

  3. Impact of Radio Link Unreliability on the Connectivity of Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jean-Marie Gorce

    2007-06-01

    Full Text Available Many works have been devoted to connectivity of ad hoc networks. This is an important feature for wireless sensor networks (WSNs to provide the nodes with the capability of communicating with one or several sinks. In most of these works, radio links are assumed ideal, that is, with no transmission errors. To fulfil this assumption, the reception threshold should be high enough to guarantee that radio links have a low transmission error probability. As a consequence, all unreliable links are dismissed. This approach is suboptimal concerning energy consumption because unreliable links should permit to reduce either the transmission power or the number of active nodes. The aim of this paper is to quantify the contribution of unreliable long hops to an increase of the connectivity of WSNs. In our model, each node is assumed to be connected to each other node in a probabilistic manner. Such a network is modeled as a complete random graph, that is, all edges exist. The instantaneous node degree is then defined as the number of simultaneous valid single-hop receptions of the same message, and finally the mean node degree is computed analytically in both AWGN and block-fading channels. We show the impact on connectivity of two MACs and routing parameters. The first one is the energy detection level such as the one used in carrier sense mechanisms. The second one is the reliability threshold used by the routing layer to select stable links only. Both analytic and simulation results show that using opportunistic protocols is challenging.

  4. Soliton coding for secured optical communication link

    CERN Document Server

    Amiri, Iraj Sadegh; Idrus, Sevia Mahdaliza

    2015-01-01

    Nonlinear behavior of light such as chaos can be observed during propagation of a laser beam inside the microring resonator (MRR) systems. This Brief highlights the design of a system of MRRs to generate a series of logic codes. An optical soliton is used to generate an entangled photon. The ultra-short soliton pulses provide the required communication signals to generate a pair of polarization entangled photons required for quantum keys. In the frequency domain, MRRs can be used to generate optical millimetre-wave solitons with a broadband frequency of 0?100 GHz. The soliton signals are multi

  5. Low-SNR Capacity of Parallel IM-DD Optical Wireless Channels

    KAUST Repository

    Chaaban, Anas

    2016-11-29

    The capacity of parallel intensity-modulation and direct-detection (IM-DD) optical wireless channels with total average intensity and per-channel peak intensity constraints is studied. The optimal intensity allocation at low signal-to-noise ratio (SNR) is derived, leading to the capacity-achieving onoff keying (OOK) distribution. Interestingly, while activating the strongest channel is optimal if (i) the peak intensity is fixed, this is not the case if (ii) the peak intensity is proportional to the average intensity. The minimum average optical intensity per bit is also studied, and is characterized for case (i) where it is achievable at low SNR. However, in case (ii), the average optical intensity per bit grows indefinitely as SNR decreases, indicating that lower optical intensity per bit can be achieved at moderate SNR than at low SNR.

  6. High-speed indoor optical wireless communication system with single channel imaging receiver.

    Science.gov (United States)

    Wang, Ke; Nirmalathas, Ampalavanapillai; Lim, Christina; Skafidas, Efstratios

    2012-04-09

    In this paper we experimentally investigate a gigabit indoor optical wireless communication system with single channel imaging receiver. It is shown that the use of single channel imaging receiver rejects most of the background light. This single channel imaging receiver is composed of an imaging lens and a small photo-sensitive area photodiode attached on a 2-axis actuator. The actuator and photodiode are placed on the focal plane of the lens to search for the focused light spot. The actuator is voice-coil based and it is low cost and commercially available. With this single channel imaging receiver, bit rate as high as 12.5 Gbps has been successfully demonstrated and the maximum error-free (BER20% has been achieved. When this system is integrated with our recently proposed optical wireless based indoor localization system, both high speed wireless communication and mobility can be provided to users over the entire room. Furthermore, theoretical analysis has been carried out and the simulation results agree well with the experiments. In addition, since the rough location information of the user is available in our proposed system, instead of searching for the focused light spot over a large area on the focal plane of the lens, only a small possible area needs to be scanned. By further pre-setting a proper comparison threshold when searching for the focused light spot, the time needed for searching can be further reduced.

  7. High capacity optical links for datacentre connectivity

    DEFF Research Database (Denmark)

    Tafur Monroy, Idelfonso; Usuga, Mario; Vegas Olmos, Juan José

    There is a timely and growing demand for high capacity optical data transport solutions to provide connectivity inside data centres and between data centres located at different geographical locations. The requirements for reach are in the order of 2 km for intra-datacentre and up to 100 km...

  8. Multi-Functional Fibre-Optic Microwave Links

    DEFF Research Database (Denmark)

    Gliese, Ulrik Bo

    1998-01-01

    GHz RF carrier. The frequency converting link demonstrates up-conversion of a 100 Mbit/s PSK signal from a 2 GHz carrier to a 9 GHz carrier with penalty-free transmission over 25 km of optical fibre. Finally, the transparent signal recovering link transmits a standard FM video 7.6 GHz radio...

  9. Thermal links for the implementation of an optical refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Epsteiin, Richard I [Los Alamos National Laboratory; Greenfield, Scott R [Los Alamos National Laboratory; Parker, John [HARVEY MUDD COLLEGE; Mar, David [HARVEY MUDD GOLLEGE; Von Der Porten, Steven [HARVEY MUDD COLLEGE; Hankinson, John [HARVEY MUDD COLLEGE; Byram, Kevin [HARVEY MUDD COLLEGE; Lee, Chris [HARVEY MUDD COLLEGE; Mayeda, Kai [HARVEY MUDD COLLEGE; Haskell, Richard [HARVEY MUDD COLLEGE; Yang, Qimin [HARVEY MUDD COLLEGE

    2008-01-01

    Optical refrigeration has been demonstrated by several groups of researchers, but the cooling elements have not been thermally linked to realistic heat loads in ways that achieve the desired temperatures. The ideal thermal link will have minimal surface area, provide complete optical isolation for the load, and possess high thermal conductivity. We have designed thermal links that minimize the absorption of fluoresced photons by the heat load using multiple mirrors and geometric shapes including a hemisphere, a kinked waveguide, and a tapered waveguide. While total link performance is dependent on additional factors, we have observed net transmission of photons with the tapered link as low as 0.04%. Our optical tests have been performed with a surrogate source that operates at 625 nm and mimics the angular distribution of light emitted from the cooling element of the Los Alamos solid state optical refrigerator. We have confirmed the optical performance of our various link geometries with computer simulations using CODE V optical modeling software. In addition we have used the thermal modeling tool in COMSOL MULTIPHYSICS to investigate other heating factors that affect the thermal performance of the optical refrigerator. Assuming an ideal cooling element and a nonabsorptive dielectric trapping mirror, the three dominant heating factors are (1) absorption of fluoresced photons transmitted through the thermal link, (2) blackbody radiation from the surrounding environment, and (3) conductive heat transfer through mechanical supports. Modeling results show that a 1 cm{sup 3} load can be chilled to 107 K with a 100 W pump laser. We have used the simulated steady-state cooling temperatures of the heat load to compare link designs and system configurations.

  10. Underwater optical wireless communications: depth dependent variations in attenuation.

    Science.gov (United States)

    Johnson, Laura J; Green, Roger J; Leeson, Mark S

    2013-11-20

    Depth variations in the attenuation coefficient for light in the ocean were calculated using a one-parameter model based on the chlorophyll-a concentration C(c) and experimentally-determined Gaussian chlorophyll-depth profiles. The depth profiles were related to surface chlorophyll levels for the range 0-4  mg/m², representing clear, open ocean. The depth where C(c) became negligible was calculated to be shallower for places of high surface chlorophyll; 111.5 m for surface chlorophyll 0.8communication links, calculated to be 0.0092  m⁻¹ at a wavelength of 430 nm. By combining this with satellite surface-chlorophyll data, it is possible to quantify the attenuation between any two locations in the ocean, with applications for low-noise or secure underwater communications and vertical links from the ocean surface.

  11. Experimental Characterization of LTE Wireless Links in High-Speed Trains

    Directory of Open Access Journals (Sweden)

    Tomás Domínguez-Bolaño

    2017-01-01

    Full Text Available Multimedia and data-based services experienced a nonstopping growth over the last few years. People are continuously on the move using devices to access multimedia contents or other data-based services. Due to this, railway companies are showing a great interest in deploying broadband mobile wireless networks in high-speed-trains with the aim of supporting both passenger services provisioning as well as automatic train control and signaling. Nowadays, the most widely used technology for communications between trains and the railway infrastructure is GSM for Railways (GSM-R; however, it has limited capabilities to support such advanced services. Due to its success in the mass market, Long Term Evolution (LTE seems to be the best candidate to substitute GSM-R. In this paper, we experimentally characterize the downlink between an LTE Evolved NodeB (eNodeB and a high-speed train in a commercial high-speed line. We consider two links: the one between the eNodeB and the antennas placed outdoors on the train roof, and the direct link between the eNodeB and a receiver inside the train. Such a characterization consists in assessing the path loss, the Signal to Noise Ratio, the K-Factor, the Power Delay Profile, the delay spread, and the Doppler Power Spectral Density.

  12. All-Optical envelope detection and fiber transmission of wireless signals by external injection of a DFB laser

    DEFF Research Database (Denmark)

    Prince, Kamau; Tafur Monroy, Idelfonso

    2008-01-01

    We outline a novel method for all-optical envelope detection of wireless signals by exploiting cross-gain modulation effects in a distributed feedback laser operating with optical injection. We successfully demonstrate envelope detection of a 20-GHz carrier amplitude-shift-keying modulated signal...

  13. Hybrid Ground Station Technology for RF and Optical Communication Links

    Science.gov (United States)

    Davarian, Faramaz; Hoppe, D.; Charles, J.; Vilnrotter, V.; Sehic, A.; Hanson, T.; Gam, E.

    2012-01-01

    To support future enhancements of NASA's deep space and planetary communications and tracking services, the Jet Propulsion Laboratory is developing a hybrid ground station that will be capable of simultaneously supporting RF and optical communications. The main reason for adding optical links to the existing RF links is to significantly increase the capacity of deep space communications in support of future solar system exploration. It is envisioned that a mission employing an optical link will also use an RF link for telemetry and emergency purposes, hence the need for a hybrid ground station. A hybrid station may also reduce operations cost by requiring fewer staff than would be required to operate two stations. A number of approaches and techniques have been examined. The most promising ones have been prototyped for field examination and validation.

  14. Space-Time Codes for Wireless Optical Communications

    Directory of Open Access Journals (Sweden)

    Tarokh Vahid

    2002-01-01

    Full Text Available A space-time channel coding technique is presented for overcoming turbulence-induced fading in an atmospheric optical heterodyne communication system that uses multiple transmit and receive apertures. In particular, a design criterion for minimizing the pairwise probability of codeword error in a space-time code (STC is developed from a central limit theorem approximation. This design criterion maximizes the mean-to-standard-deviation ratio of the received energy difference between codewords. It leads to STCs that are a subset of the previously reported STCs for Rayleigh channels, namely those created from orthogonal designs. This approach also extends to other fading channels with independent, zero-mean path gains. Consequently, for large numbers of transmit and receive antennas, STCs created from orthogonal designs minimize the pairwise codeword error probability for this larger class of fading channels.

  15. Asymptotic Performance Analysis of the k-th Best Link Selection over Wireless Fading Channels: An Extreme Value Theory Approach

    KAUST Repository

    Al-Badarneh, Yazan Hussein

    2018-01-25

    We consider a general selection-diversity (SD) scheme in which the k-th best link is selected from a number of links. We use extreme value theory (EVT) to derive simple closed-form asymptotic expressions for the average throughput, effective throughput and average bit error probability (BEP) for the k-th best link over various channel models that are widely used to characterize fading in wireless communication systems. As an application example, we consider the Weibull fading channel model and verify the accuracy of the derived asymptotic expressions through Monte Carlo simulations.

  16. Energy Harvesting Hybrid Acoustic-Optical Underwater Wireless Sensor Networks Localization

    KAUST Repository

    Saeed, Nasir

    2017-12-26

    Underwater wireless technologies demand to transmit at higher data rate for ocean exploration. Currently, large coverage is achieved by acoustic sensor networks with low data rate, high cost, high latency, high power consumption, and negative impact on marine mammals. Meanwhile, optical communication for underwater networks has the advantage of the higher data rate albeit for limited communication distances. Moreover, energy consumption is another major problem for underwater sensor networks, due to limited battery power and difficulty in replacing or recharging the battery of a sensor node. The ultimate solution to this problem is to add energy harvesting capability to the acoustic-optical sensor nodes. Localization of underwater sensor networks is of utmost importance because the data collected from underwater sensor nodes is useful only if the location of the nodes is known. Therefore, a novel localization technique for energy harvesting hybrid acoustic-optical underwater wireless sensor networks (AO-UWSNs) is proposed. AO-UWSN employs optical communication for higher data rate at a short transmission distance and employs acoustic communication for low data rate and long transmission distance. A hybrid received signal strength (RSS) based localization technique is proposed to localize the nodes in AO-UWSNs. The proposed technique combines the noisy RSS based measurements from acoustic communication and optical communication and estimates the final locations of acoustic-optical sensor nodes. A weighted multiple observations paradigm is proposed for hybrid estimated distances to suppress the noisy observations and give more importance to the accurate observations. Furthermore, the closed form solution for Cramer-Rao lower bound (CRLB) is derived for localization accuracy of the proposed technique.

  17. Energy Harvesting Hybrid Acoustic-Optical Underwater Wireless Sensor Networks Localization

    Directory of Open Access Journals (Sweden)

    Nasir Saeed

    2017-12-01

    Full Text Available Underwater wireless technologies demand to transmit at higher data rate for ocean exploration. Currently, large coverage is achieved by acoustic sensor networks with low data rate, high cost, high latency, high power consumption, and negative impact on marine mammals. Meanwhile, optical communication for underwater networks has the advantage of the higher data rate albeit for limited communication distances. Moreover, energy consumption is another major problem for underwater sensor networks, due to limited battery power and difficulty in replacing or recharging the battery of a sensor node. The ultimate solution to this problem is to add energy harvesting capability to the acoustic-optical sensor nodes. Localization of underwater sensor networks is of utmost importance because the data collected from underwater sensor nodes is useful only if the location of the nodes is known. Therefore, a novel localization technique for energy harvesting hybrid acoustic-optical underwater wireless sensor networks (AO-UWSNs is proposed. AO-UWSN employs optical communication for higher data rate at a short transmission distance and employs acoustic communication for low data rate and long transmission distance. A hybrid received signal strength (RSS based localization technique is proposed to localize the nodes in AO-UWSNs. The proposed technique combines the noisy RSS based measurements from acoustic communication and optical communication and estimates the final locations of acoustic-optical sensor nodes. A weighted multiple observations paradigm is proposed for hybrid estimated distances to suppress the noisy observations and give more importance to the accurate observations. Furthermore, the closed form solution for Cramer-Rao lower bound (CRLB is derived for localization accuracy of the proposed technique.

  18. Energy Harvesting Hybrid Acoustic-Optical Underwater Wireless Sensor Networks Localization.

    Science.gov (United States)

    Saeed, Nasir; Celik, Abdulkadir; Al-Naffouri, Tareq Y; Alouini, Mohamed-Slim

    2017-12-26

    Underwater wireless technologies demand to transmit at higher data rate for ocean exploration. Currently, large coverage is achieved by acoustic sensor networks with low data rate, high cost, high latency, high power consumption, and negative impact on marine mammals. Meanwhile, optical communication for underwater networks has the advantage of the higher data rate albeit for limited communication distances. Moreover, energy consumption is another major problem for underwater sensor networks, due to limited battery power and difficulty in replacing or recharging the battery of a sensor node. The ultimate solution to this problem is to add energy harvesting capability to the acoustic-optical sensor nodes. Localization of underwater sensor networks is of utmost importance because the data collected from underwater sensor nodes is useful only if the location of the nodes is known. Therefore, a novel localization technique for energy harvesting hybrid acoustic-optical underwater wireless sensor networks (AO-UWSNs) is proposed. AO-UWSN employs optical communication for higher data rate at a short transmission distance and employs acoustic communication for low data rate and long transmission distance. A hybrid received signal strength (RSS) based localization technique is proposed to localize the nodes in AO-UWSNs. The proposed technique combines the noisy RSS based measurements from acoustic communication and optical communication and estimates the final locations of acoustic-optical sensor nodes. A weighted multiple observations paradigm is proposed for hybrid estimated distances to suppress the noisy observations and give more importance to the accurate observations. Furthermore, the closed form solution for Cramer-Rao lower bound (CRLB) is derived for localization accuracy of the proposed technique.

  19. Bounds on Minimum Energy per Bit for Optical Wireless Relay Channels

    Directory of Open Access Journals (Sweden)

    A. D. Raza

    2014-09-01

    Full Text Available An optical wireless relay channel (OWRC is the classical three node network consisting of source, re- lay and destination nodes with optical wireless connectivity. The channel law is assumed Gaussian. This paper studies the bounds on minimum energy per bit required for reliable communication over an OWRC. It is shown that capacity of an OWRC is concave and energy per bit is monotonically increasing in square of the peak optical signal power, and consequently the minimum energy per bit is inversely pro- portional to the square root of asymptotic capacity at low signal to noise ratio. This has been used to develop upper and lower bound on energy per bit as a function of peak signal power, mean to peak power ratio, and variance of channel noise. The upper and lower bounds on minimum energy per bit derived in this paper correspond respectively to the decode and forward lower bound and the min-max cut upper bound on OWRC capacity

  20. Power optimization of wireless optical communication with log-square-Ricean fading.

    Science.gov (United States)

    Liu, X

    2012-07-01

    It has been important to optimize the transmitter power in wireless optical communication systems. The conventional approach was based on the reciprocal Pareto model. In this paper, the investigation is extended to a more general scenario where the instantaneous signal-to-noise ratio follows the log-square-Ricean distribution. Accordingly, the optimization model is established. The conventional model thus becomes a special case of the new model. It is shown that the new model can be analytically solved. The sample solutions clearly show how the optima of transmitter power change when the log-square-Ricean profile changes. These results would provide useful guidelines to system design.

  1. Subcarrier MPSK/MDPSK modulated optical wireless communications in lognormal turbulence

    KAUST Repository

    Song, Xuegui

    2015-03-01

    Bit-error rate (BER) performance of subcarrier Mary phase-shift keying (MPSK) and M-ary differential phase-shift keying (MDPSK) is analyzed for optical wireless communications over the lognormal turbulence channels. Both exact BER and approximate BER expressions are presented. We demonstrate that the approximate BER, which is obtained by dividing the symbol error rate by the number of bits per symbol, can be used to estimate the BER performance with acceptable accuracy. Through our asymptotic analysis, we derive closed-form asymptotic BER performance loss expression for MDPSK with respect to MPSK in the lognormal turbulence channels. © 2015 IEEE.

  2. Simple statistical channel model for weak temperature-induced turbulence in underwater wireless optical communication systems

    KAUST Repository

    Oubei, Hassan M.

    2017-06-16

    In this Letter, we use laser beam intensity fluctuation measurements to model and describe the statistical properties of weak temperature-induced turbulence in underwater wireless optical communication (UWOC) channels. UWOC channels with temperature gradients are modeled by the generalized gamma distribution (GGD) with an excellent goodness of fit to the measured data under all channel conditions. Meanwhile, thermally uniform channels are perfectly described by the simple gamma distribution which is a special case of GGD. To the best of our knowledge, this is the first model that comprehensively describes both thermally uniform and gradient-based UWOC channels.

  3. Optimum LED wavelength for underwater optical wireless communication at turbid water

    Science.gov (United States)

    Rosenkrantz, Etai; Arnon, Shlomi

    2014-10-01

    Underwater optical wireless communication is an emerging technology, which can provide high data rate. High data rate communication is required for applications such as underwater imaging, networks of sensors and swarms of underwater vehicles. These applications pursue an affordable light source, which can be obtained by light emitting diodes (LED). LEDs offer solutions characterized by low cost, high efficiency, reliability and compactness based on off-the-shelf components such as blue and green light emitting diodes. In this paper we present our recent theoretical and experimental results in this field.

  4. Optimization of locations of diffusion spots in indoor optical wireless local area networks

    Science.gov (United States)

    Eltokhey, Mahmoud W.; Mahmoud, K. R.; Ghassemlooy, Zabih; Obayya, Salah S. A.

    2018-03-01

    In this paper, we present a novel optimization of the locations of the diffusion spots in indoor optical wireless local area networks, based on the central force optimization (CFO) scheme. The users' performance uniformity is addressed by using the CFO algorithm, and adopting different objective function's configurations, while considering maximization and minimization of the signal to noise ratio and the delay spread, respectively. We also investigate the effect of varying the objective function's weights on the system and the users' performance as part of the adaptation process. The results show that the proposed objective function configuration-based optimization procedure offers an improvement of 65% in the standard deviation of individual receivers' performance.

  5. 40  Gb/s indoor optical wireless system enabled by a cyclically arranged optical beamsteering receiver.

    Science.gov (United States)

    Zhang, Xuebing; Liu, Yu; Cao, Zizheng; Li, Fan; Li, Zhaohui; Ismaeel, R; Brambilla, G; Chen, Y; Koonen, A M J

    2018-02-15

    Indoor optical wireless communication with optical beamsteering capability is currently attracting a lot of attention. One major two-dimensional (2D) optical beamsteering scheme is realized by 2D grating or its active counterpart, which is usually based on a spatial light modulator (SLM). However, there is a fundamental trade-off between the field of view (FoV) and power efficiency due to the inherent feature of gratings. In this Letter, we propose a new class of 2D beamsteering, named cyclically arranged optical beamsteering (CAO-BS), which can break that trade-off. Traditional 2D gratings extend the optical beam in the Cartesian coordinates (1D grating in horizontal + 1D grating in vertical), while CAO-BS extends the optical beam in the polar coordinates (1D grating + angular rotation). Since only 1D grating is engaged, the power efficiency increases with the number of grating lobes reduced. In the polar coordinates, the angle rotation tuning in a SLM is quasi-continuous in a full 2π range. The CAO-BS is demonstrated at the receiving end in an indoor experimental system. The FoV is 18° by 360° in polar coordinates without any additional mechanical parts. Based on the CAO-BS, 40 Gbit/s on-off keying data is also successfully transmitted over 1 km single-mode fiber and 0.5 m free space.

  6. Buckshot Routing with Distance Vectors in Three Application Scenarios for Wireless Sensor Networks with Unstable Network Topologies and Unidirectional Links

    Directory of Open Access Journals (Sweden)

    Reinhardt Karnapke

    2015-02-01

    Full Text Available Experiments have shown that the number of asymmetric and unidirectional links often exceeds the number of bidirectional ones, especially in the transitional area of the communication range of wireless sensor nodes. Still, most of today’s routing protocols ignore their existence or try to remove their implications. Also, links are not stable over time, and routes become unusable often, resulting in a need for new routing protocols that can handle highly dynamic links and use unidirectional links to their advantage. At SENSORCOMM' 2014, we presented BuckshotDV, a routing protocol which is resilient against link fluctuations and uses the longer reach of unidirectional links to increase its performance. Furthermore, its distance vector nature makes it scalable for large sensor networks. This paper is an extended version which adds some implementation details and the evaluation of BuckshotDV in two more application scenarios.

  7. Conclusions of ESA 1st Optical Wireless Onboard Communications Workshop: Current Status and the Road Forward

    National Research Council Canada - National Science Library

    Hernandez, Inmaculada; Plancke, Patrick

    2005-01-01

    ...) Review the state-of-the-art of optical free space communications in ground and in space, in short- and medium-link distances, point-to-point, as well as broadcast or other networking schemes; (2...

  8. Vibration reduction for commercial optical intersatellite communication links

    Science.gov (United States)

    Hyde, T. Tupper; Davis, L. Porter

    1998-07-01

    The increasing demand for global communications and limitations on RF communication bandwidth has driven several corporations to baseline optical intersatellite communication links in their constellations. The use of laser communications over a long distance dictates the need for accurate pointing and jitter suppression in order to maintain signal. Vibrations on a satellite cause excessive line-of-sight jitter for optical performance. The solution to these vibration sources is a systems problem involving optical control of coarse and fine steering, vibration isolation of the optical payload, or reduction of the spacecraft disturbances. This paper explains the basics of tracking control of a laser communication package and details the systems trades for vibration isolation. Simulation results based on a vibration isolation and precision pointing of a hypothetical commercial LEO to LEO 4 Gbit/sec laser cross-link system are presented.

  9. Link and route availability for Inter-working multi-hop wireless networks

    CSIR Research Space (South Africa)

    Salami, O

    2009-09-01

    Full Text Available In inter-working multi-hop wireless networks, establishing resilient connectivity between source-destination node pairs is a major issue. The issue of connectivity in multi-hop wireless networks have been studied. However, these analyses focused...

  10. 225m Outdoor W-Band Radio-over-Fiber Link Using an Optical SFP+ Module

    DEFF Research Database (Denmark)

    Rommel, Simon; Rodríguez Páez, Juan Sebastián; Chorchos, Łukasz

    2016-01-01

    A W-band radio-over-fiber link based on a commercial SFP+ module is demonstrated, allowing easy integration into existing PON solutions. Without active laser control good RF frequency stability and 225m wireless distance are achieved......A W-band radio-over-fiber link based on a commercial SFP+ module is demonstrated, allowing easy integration into existing PON solutions. Without active laser control good RF frequency stability and 225m wireless distance are achieved...

  11. Overview of the RICH Optical Data Link and Evaluation of its Optical Attenuation

    CERN Document Server

    Powell, A S

    2006-01-01

    The RICH optical link is required to transport the Gigabit/s data flow from the on-detector Level 0 front-end boards to the Level 1 receiver electronics located approximately 100 meters away in the counting room. To ensure the light intensity observed at the Level 1 end of the optical link is compatible with the optical receiver specifications, a knowledge of the optical attenuation across the proposed link is necessary. This report presents the results obtained from performing attenuation tests on the RICH optical link and its constituent interfaces. These results are then used to predict the absolute maximum and minimum light intensities that would be expected at the Level 1 optical receiver when the data link is driven by the Level 0 optical transmitter, the VCSEL. To confirm these results explicitly, Bit Error Rate (BER) tests were performed using a variable optical attenuator inserted into the data link. The report concludes that by operating the VCSEL with a baseline driving current below 4.2 mA the RIC...

  12. Optimization of data coils in a multiband wireless link for neuroprosthetic implantable devices.

    Science.gov (United States)

    Uei-Ming Jow; Ghovanloo, M

    2010-10-01

    We have presented the design methodology along with detailed simulation and measurement results for optimizing a multiband transcutaneous wireless link for high-performance implantable neuroprosthetic devices. We have utilized three individual carrier signals and coil/antenna pairs for power transmission, forward data transmission from outside into the body, and back telemetry in the opposite direction. Power is transmitted at 13.56 MHz through a pair of printed spiral coils (PSCs) facing each other. Two different designs have been evaluated for forward data coils, both of which help to minimize power carrier interference in the received data carrier. One is a pair of perpendicular coils that are wound across the diameter of the power PSCs. The other design is a pair of planar figure-8 coils that are in the same plane as the power PSCs. We have compared the robustness of each design against horizontal misalignments and rotations in different directions. Simulation and measurements are also conducted on a miniature spiral antenna, designed to operate with impulse-radio ultra-wideband (IR-UWB) circuitry for back telemetry.

  13. A Power-Efficient Wireless Capacitor Charging System Through an Inductive Link.

    Science.gov (United States)

    Lee, Hyung-Min; Ghovanloo, Maysam

    2013-10-01

    A power-efficient wireless capacitor charging system for inductively powered applications has been presented. A bank of capacitors can be directly charged from an ac source by generating a current through a series charge injection capacitor and a capacitor charger circuit. The fixed charging current reduces energy loss in switches, while maximizing the charging efficiency. An adaptive capacitor tuner compensates for the resonant capacitance variations during charging to keep the amplitude of the ac input voltage at its peak. We have fabricated the capacitor charging system prototype in a 0.35- μ m 4-metal 2-poly standard CMOS process in 2.1 mm 2 of chip area. It can charge four pairs of capacitors sequentially. While receiving 2.7-V peak ac input through a 2-MHz inductive link, the capacitor charging system can charge each pair of 1 μ F capacitors up to ±2 V in 420 μ s, achieving a high measured charging efficiency of 82%.

  14. Implementation of an Optical-Wireless Network with Spectrum Sensing and Dynamic Resource Allocation Using Optically Controlled Reconfigurable Antennas

    Directory of Open Access Journals (Sweden)

    E. Raimundo-Neto

    2014-01-01

    Full Text Available This work proposes the concept and reports the implementation of an adaptive and cognitive radio over fiber architecture. It is aimed at dealing with the new demands for convergent networks by means of simultaneously providing the functionalities of multiband radiofrequency spectrum sensing, dynamic resource allocation, and centralized processing capability, as well as the use of optically controlled reconfigurable antennas and radio over fiber technology. The performance of this novel and innovative architecture has been evaluated in a geographically distributed optical-wireless network under real conditions and for different fiber lengths. Experimental results demonstrate reach extension of more than 40 times and an enhancement of more than 30 dB in the carrier to interference plus noise ratio parameter.

  15. Optimal optical communication terminal structure for maximizing the link budget

    Science.gov (United States)

    Huang, Jian; Jiang, Dagang; Deng, Ke; Zhang, Peng

    2015-02-01

    Ordinary inter-satellite optical includes at least three optical paths for acquisition, tracking and communication, the three optical paths work simultaneously and share the received power. An optimal structure of inter-satellite optical communication terminal with single working optical path at each of working stages of acquisition and communication is introduced. A space optical switch based on frustrated total internal reflection effect is applied to switch the received laser power between the acquisition sensor and the communication sensor between the stages of acquisition and communication, this is named as power fusion which means power is transferred for shutting down unused optical path. For the stages of tracking and communication, a multiple cells sensor is used to accomplish the operation of tracking while communication, this is named as function fusion which means accomplishing multiple functions by one device to reduce the redundant optical paths. For optical communication terminal with single working path structure, the total received laser power would be detected by one sensor for each different stages of acquisition, tracking and communication, the link budget would be maximized, and this design would help to enlarge the system tolerance and reduce the acquisition time.

  16. Average capacity for optical wireless communication systems over exponentiated Weibull distribution non-Kolmogorov turbulent channels.

    Science.gov (United States)

    Cheng, Mingjian; Zhang, Yixin; Gao, Jie; Wang, Fei; Zhao, Fengsheng

    2014-06-20

    We model the average channel capacity of optical wireless communication systems for cases of weak to strong turbulence channels, using the exponentiation Weibull distribution model. The joint effects of the beam wander and spread, pointing errors, atmospheric attenuation, and the spectral index of non-Kolmogorov turbulence on system performance are included. Our results show that the average capacity decreases steeply as the propagation length L changes from 0 to 200 m and decreases slowly down or tends to a stable value as the propagation length L is greater than 200 m. In the weak turbulence region, by increasing the detection aperture, we can improve the average channel capacity and the atmospheric visibility as an important issue affecting the average channel capacity. In the strong turbulence region, the increase of the radius of the detection aperture cannot reduce the effects of the atmospheric turbulence on the average channel capacity, and the effect of atmospheric visibility on the channel information capacity can be ignored. The effect of the spectral power exponent on the average channel capacity in the strong turbulence region is higher than weak turbulence region. Irrespective of the details determining the turbulent channel, we can say that pointing errors have a significant effect on the average channel capacity of optical wireless communication systems in turbulence channels.

  17. Performance improvement of optical wireless communication through fog with a decision feedback equalizer.

    Science.gov (United States)

    Aharonovich, Marius; Arnon, Shlomi

    2005-08-01

    Optical wireless communication (OWC) systems use the atmosphere as a propagation medium. However, a common problem is that from time to time moderate cloud and fog emerge between the receiver and the transmitter. These adverse weather conditions impose temporal broadening and power loss on the optical signal, which reduces the digital signal-to-noise ratio (DSNR), produces significant intersymbol interference (ISI), and degrades the communication system's bit error rate (BER) and throughput. We propose and investigate the use of a combined adaptive bandwidth mechanism and decision feedback equalizer (DFE) to mitigate these atmospheric multipath effects. Based on theoretical analysis and simulations of DSNR penalties, BER, and optimum system bandwidths, we show that a DFE improves the outdoor OWC system immunity to ISI in foggy weather while maintaining high throughput and desired low BER.

  18. Underwater wireless optical communication using a blue-light leaky feeder

    Science.gov (United States)

    Xu, Jing; Sun, Bin; Kong, Meiwei; Lin, Aobo; Sarwar, Rohail; Han, Jun; Zhang, Wei; Deng, Ning

    2017-08-01

    A novel concept of using a leaky plastic optical fiber (POF) as the leaky feeder for underwater wireless optical communication (UWOC) is proposed and experimentally demonstrated. The leaky POF can potentially improve the UWOC coverage. Orthogonal frequency division multiplexing (OFDM) is employed in the demonstration to increase spectral efficiency and robustness to modal dispersion of the leaky POF with a large core. A bit rate of 224.61 Mb/s (net bit rate: 183.69 Mb/s) at the two discrete radiation points along a 10-m leaky POF feeder is achieved using 16-quadrature amplitude modulation (QAM)-OFDM modulation. Over a 30-cm underwater channel, the mean bit errors (BERs) measured at the two points are 3.37×10-5 and 3.35×10-3, respectively, which are below the FEC threshold of 3.8×10-3.

  19. Energy-efficient multidimensional Hellinger modulation for SPAD-based optical wireless communications.

    Science.gov (United States)

    Si-Ma, Ling-Han; Zhang, Jian; Wang, Bin-Qiang; Zhang, Yan-Yu

    2017-09-18

    Recently, the single photon avalanche diode optical wireless communication (SPAD OWC) has attracted much attention due to its potential underwater applications. For such system, the channel noise is additive Poisson noise (APN) rather than the commonly encountered additive white Gaussian noise (AWGN) and the corresponding maximum likelihood (ML) detection is hard to provide a useful insight into energy-efficient signal design. By using the previously proposed Hellinger distance design criterion, we design an energy-efficient multi-dimensional constellation within the nonnegative integer set by minimizing the average optical power for a fixed minimum Hellinger distance. Comprehensive simulations indicate that our designed constellation can substantially outperform the currently available pulse amplitude modulation (PAM) and squared PAM for SPAD OWC systems.

  20. A Review on Radio-Over-Fiber Technology-Based Integrated (Optical/Wireless) Networks

    Science.gov (United States)

    Rajpal, Shivika; Goyal, Rakesh

    2017-06-01

    In the present paper, radio-over-fiber (RoF) technology has been proposed, which is the integration of the optical and radio networks. With a high transmission capacity, comparatively low cost and low attenuation, optical fiber provides an ideal solution for accomplishing the interconnections. In addition, a radio system enables the significant mobility, flexibility and easy access. Therefore, the system integration can meet the increasing demands of subscribers for voice, data and multimedia services that require the access network to support high data rates at any time and any place inexpensively. RoF has the potentiality to the backbone of the wireless access network and it has gained significant momentum in the last decade as a potential last-mile access scheme. This paper gives the comprehensive review of RoF technology used in the communication system. Concept, applications, advantages and limitations of RoF technology are also discussed in this paper.

  1. On the power and offset allocation for rate adaptation of spatial multiplexing in optical wireless MIMO channels

    KAUST Repository

    Park, Kihong

    2011-07-01

    Visible light communication (VLC) using optical sources which can be simultaneously utilized for illumination and communication is currently an attractive option for wireless personal area network. Improving the data rate in optical wireless communication system is challenging due to the limited bandwidth of the optical sources. In this paper, we design the singular value decomposition (SVD)- based multiplexing multiple-input multiple-output (MIMO) system to support two data streams in optical wireless channels. Noting that the conventional allocation method in radio frequency (RF) MIMO channels cannot be applied directly to the optical intensity channels, we propose a novel method to allocate the optical power, the offset value and the modulation size for maximum sum rate under the constraints of the nonnegativity of the modulated signals, the aggregate optical power and the bit error rate (BER) requirement. The simulation results show that the proposed allocation method gives the better performance than the method to allocate the optical power equally for each data stream. © 2011 IEEE.

  2. Miniaturized Optical Data Link Assembly for 360 um Guidewires

    NARCIS (Netherlands)

    Stoute, R.; Louwerse, M.C.; Van Rens, J.; Henneken, V.A.; Dekker, R.

    2015-01-01

    We propose a novel concept for a high-speed optical data link in Ø 360 µm cardiovascular interventional imaging guidewires. The concept is based on the recently introduced Flex-to-Rigid (F2R) technology platform. This technology allows for smaller intravascular imaging devices with a more compact

  3. Channel characterization for high-speed W-band wireless communication links

    DEFF Research Database (Denmark)

    Rommel, Simon; Cavalcante, Lucas Costa Pereira; Vegas Olmos, Juan José

    2015-01-01

    We present and discuss results from an experimental characterization of the W-band indoor wireless channel, including both large and small scale fading phenomena as well as corresponding channel parameters and their impact on system performance....

  4. Reverse polarity optical-OFDM (RPO-OFDM): dimming compatible OFDM for gigabit VLC links.

    Science.gov (United States)

    Elgala, Hany; Little, Thomas D C

    2013-10-07

    Visible light communications (VLC) technology permits the exploitation of light-emitting diode (LED) luminaries for simultaneous illumination and broadband wireless communication. Optical orthogonal frequency-division multiplexing (O-OFDM) is a promising modulation technique for VLC systems, in which the real-valued O-OFDM baseband signal is used to modulate the instantaneous power of the optical carrier to achieve gigabit data rates. However, a major design challenge that limits the commercialization of VLC is how to incorporate the industry-preferred pulse-width modulation (PWM) light dimming technique while maintaining a broadband and reliable communication link. In this work, a novel signal format, reverse polarity O-OFDM (RPO-OFDM), is proposed to combine the fast O-OFDM communication signal with the relatively slow PWM dimming signal, where both signals contribute to the effective LED brightness. The advantages of using RPO-OFDM include, (1) the data rate is not limited by the frequency of the PWM signal, (2) the LED dynamic range is fully utilized to minimize the nonlinear distortion of the O-OFDM communication signal, and (3) the bit-error performance is sustained over a large fraction of the luminaire dimming range. In addition, RPO-OFDM offers a practical approach to utilize off-the-shelf LED drivers. We show results of numerical simulations to study the trade-offs between the PWM duty cycle, average electrical O-OFDM signal power, radiated optical flux as well as human perceived light.

  5. Short distance optical links: Analysis, demonstration and circuit design

    Science.gov (United States)

    Pappu, Anand Mohan

    Optical signaling has some fundamental advantages over electrical signaling. Some of these advantages like absence of parasitics have been utilized beneficially in long distance and medium distance interconnection networks. However, for optics to be useful in the highly optimized and constrained VLSI system space, we require more benefits from using optics. In this dissertation, I identify electrical isolation of optical interconnects as an additional benefit. I study how this advantage can make optical interconnects beneficial in modern VLSI systems at short distances and have taken a step towards solving chip-to-chip and intra-chip interconnection issues. I demonstrate using our proof-of-concept circuits, the benefits of using optical fanout in electrical links with fanout. I show improved signal latency with optical fanout even at link lengths of 200mum in a 0.25mum technology. This is the first physical demonstration of the advantages of using optics in silicon VLSI systems at these distances. I also demonstrated an advantage in energy-delay-squared product for fanout to more than 250 minimum sized inverters corresponding to a distance of 1.5 mm. I also demonstrate an important step towards physical implementation of our proposed short-distance optical links via our design of a silicon-based detector. I developed our detector in a commercial process and it uses a low supply voltage 1.8V. These features make our detector extremely low-cost and readily available in commercial processes. I also demonstrate opto-electronic integration of detectors and receivers in the same silicon chip and show operation at 1Gbps link bit rate. As a part of our circuit design efforts for optimal link design, I focused on creating process-invariant circuits. Fabrication related circuit variations lead to a significant power-performance-yield trade-off and introduce variability in the various branches of optical fanout. Addressing these issues is necessary in constructing a robust

  6. High-Capacity Wireless Signal Generation and Demodulation in 75- to 110-GHz Band Employing All-Optical OFDM

    DEFF Research Database (Denmark)

    Zibar, Darko; Sambaraju, Rakesh; Caballero Jambrina, Antonio

    2011-01-01

    We present a radio-frequency (RF) and bit-rate scalable technique for multigigabit wireless signal generation based on all-optical orthogonal frequency-division multiplexing (OFDM) and photonic up-conversion. Coherent detection supported by digital signal processing is used for signal demodulation...

  7. The Optical Links of the ATLAS SemiConductor Tracker

    CERN Document Server

    Abdesselam, A; Apsimon, R; Band, C; Barr, C; Batchelor, L; Bates, R; Bell, P; Bernabeu, J; Bizzell, J; Brenner, R; Brodbeck, T; Bruckman De Renstrom, P; Buttar, C; Carter, J; Charlton, D; Cheplakov, A; Chilingarov, A; Chu, M-L; Colijn, A-P; Dawson, I; Demirkõz, B; de Jong, P; Dervan, P; Dolezal, Z; Dowell, J; Escobar, P; Spencer, E; Ekelöf, T J C; Eklund, L; Ferrere, D; Fraser, T; French, M; French, R; Fuster, J; Gallop, B; García, C; Goodrick, M; Greenall, A; Grillo, A; Grosse-Knetter, J; Hartjes, F; Hessey, N; Hill, J C; Homer, J; Hou, L; Hughes, G; Ikegami, Y; Issever, C; Jackson, J; Jones, M; Jones, T J; Jovanovic, P; Koffeman, E; Kodys, P; Kohriki, T; Lee, S-C; Lester, C; Limper, M; Lindsay, S W; Lozano, M; Macwaters, C; Magrath, C; Mahout, G; Mandic, I; Matheson, J; McMahon, T; Mikulec, B; Muijs, A; Morrissey, M; Nichols, A; Nickerson, R; O'Shea, V; Pagenis, S; Parker, M; Pater, J; Perrin, E; Pernegger, H; Peeters, S; Phillips, P; Postranecky, M; Robinson, D; Robson, A; Rudge, A; Sandaker, H; Sedlak, K; Smith, N A; Stapnes, S; Stugu, B; Teng, P K; Terada, S; Tricoli, A; Tyndel, M; Ujiie, N; Ullán, M; Unno, Y; van der Kraaij, E; Van Vulpen, I; Viehhauser, G; Vossebeld, J H; Warren, M; Wastie, R; Weidberg, A; Wells, P; White, D; Wilson, J

    2007-01-01

    Optical links are used for the readout of the 4088 silicon microstrip modules that make up the SemiConductor Tracker of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The optical link requirements are reviewed, with particular emphasis on the very demanding environment at the LHC. The on-detector components have to operate in high radiation levels for 10 years, with no maintenance, and there are very strict requirements on power consumption, material and space. A novel concept for the packaging of the on-detector optoelectronics has been developed to meet these requirements. The system architecture, including its redundancy features, is explained and the critical on-detector components are described. The results of the extensive Quality Assurance performed during all steps of the assembly are discussed. Optical links are used for the readout of the 4088 silicon microstrip modules that make up the SemiConductor Tracker of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The optical ...

  8. Optical coherence tomography in x-linked adrenoleukodystrophy.

    Science.gov (United States)

    Aquino, Jannelle J; Sotirchos, Elias S; Saidha, Shiv; Raymond, Gerald V; Calabresi, Peter A

    2013-09-01

    X-linked adrenoleukodystrophy is a metabolic disease caused by mutations in the ABCD1 gene, which codes for a peroxisomal membrane protein, leading to the accumulation of very long-chain fatty acids. Thinning of the retinal nerve fiber layer and macula has been described in adult-onset adrenomyeloneuropathy; however, assessment of these structures in the presymptomatic stage remains largely unexplored. Optical coherence tomography is a high-resolution medical imaging technology that has been widely used to assess ophthalmological diseases and more recently in neurological disease states to quantify the axonal and neuronal injury in the retina that results from demyelination of the optic nerve. Fourteen boys with presymptomatic X-linked adrenoleukodystrophy and 14 age-matched healthy controls underwent retinal imaging with optical coherence tomography. Optical coherence tomography-derived retinal thickness measures did not differ between adrenoleukodystrophy subjects and healthy controls. Our results suggest that structural retinal abnormalities are not detectable before the development of neurological manifestations in adrenoleukodystrophy. Further investigation of the utility of optical coherence tomography scanning in individuals with symptomatic disease should be considered to determine if its measures could be used as a biomarker of disease progression. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. A 10 Mbyte/s fiber optic link

    International Nuclear Information System (INIS)

    Brodier-Yourstone, P.; McCulloch, L.; McLaren, R.A.

    1995-01-01

    This paper presents a fiber optic link (FOL) that has been developed for the NA48 experiment at CERN. About 15 FOLs will be used to transfer event data to the Data Merger (event builder) over a distance of 200 meters. The FOL has a very simple interface and is capable of transmitting data at a rate of over 10 Mbyte/s while performing error detection. The optical part of the FOL uses industry standard components. This, combined with its simplicity of use, makes the FOL suitable to be reused in a wide range of applications, which is shown by its use outside the NA48 experiment

  10. Using the combination refraction-reflection solid to design omni-directional light source used in underwater wireless optical communication

    Science.gov (United States)

    Rao, Jionghui; Yao, Wenming; Wen, Linqiang

    2015-10-01

    Underwater wireless optical communication is a communication technology which uses laser as an information carrier and transmits data through water. Underwater wireless optical communication has some good features such as broader bandwidth, high transmission rate, better security, anti—interference performance. Therefore, it is promising to be widely used in the civil and military communication domains. It is also suitable for high-speed, short-range communication between underwater mobile vehicles. This paper presents a design approach of omni-directional light source used in underwater wireless optical communication, using TRACEPRO simulation tool to help design a combination solid composed of the lens, conical reflector and parabolic reflector, and using the modulated DPSS green laser in the transmitter module to output the laser beam in small divergence angles, after expanded by the combination refraction-reflection solid, the angle turns into a space divergence angle of 2π, achieving the omni-directional light source of hemisphere space, and test in the air and underwater, the result shows that the effect is fine. This paper analyzes the experimental test in the air and water, in order to make further improvement of the uniformity of light distribution, we optimize the reflector surface parameters of combination refraction-reflection solid and test in the air and water. The result shows that omni-directional light source used in underwater wireless optical communication optimized could achieve the uniformity of light distribution of underwater space divergence angle of 2π. Omni-directional light source used in underwater wireless optical communication designed in this paper has the characteristics of small size and uniformity of light distribution, it is suitable for application between UUVs, AUVs, Swimmer Delivery Vehicles (SDVs) and other underwater vehicle fleet, it realizes point-to-multipoint communications.

  11. Optical network unit placement in Fiber-Wireless (FiWi) access network by Moth-Flame optimization algorithm

    Science.gov (United States)

    Singh, Puja; Prakash, Shashi

    2017-07-01

    Hybrid wireless-optical broadband access network (WOBAN) or Fiber-Wireless (FiWi) is the integration of wireless access network and optical network. This hybrid multi-domain network adopts the advantages of wireless and optical domains and serves the demand of technology savvy users. FiWi exhibits the properties of cost effectiveness, robustness, flexibility, high capacity, reliability and is self organized. Optical Network Unit (ONU) placement problem in FiWi contributes in simplifying the network design and enhances the performance in terms of cost efficiency and increased throughput. Several individual-based algorithms, such as Simulated Annealing (SA), Tabu Search, etc. have been suggested for ONU placement, but these algorithms suffer from premature convergence (trapping in a local optima). The present research work undertakes the deployment of FiWi and proposes a novel nature-inspired heuristic paradigm called Moth-Flame optimization (MFO) algorithm for multiple optical network units' placement. MFO is a population based algorithm. Population-based algorithms are better in handling local optima avoidance. The simulation results are compared with the existing Greedy and Simulated Annealing algorithms to optimize the position of ONUs. To the best of our knowledge, MFO algorithm has been used for the first time in this domain, moreover it has been able to provide very promising and competitive results. The performance of MFO algorithm has been analyzed by varying the 'b' parameter. MFO algorithm results in faster convergence than the existing strategies of Greedy and SA and returns a lower value of overall cost function. The results exhibit the dependence of the objective function on the distribution of wireless users also.

  12. A wireless optical power system for medical implants using low power near-IR laser.

    Science.gov (United States)

    Saha, A; Iqbal, S; Karmaker, M; Zinnat, S F; Ali, M T

    2017-07-01

    An alternative method of transcutaneous wireless optical energy supply to an artificial cardiac pacemaker has been conceived, thereby negating the possibility of electromagnetic interference. In this research, a comparative analysis is made between two distinct arrays of photovoltaic cells, consisting of two different geometries. Being powered by a 5 mW 750 nm laser, that has a different spot size for each topology; both models are tested by their ability to charge a 150 mAh rechargeable LiPo battery, while being embedded underneath a layer of skin tissue. This system in turn, regulates the power supplied to a low power medical implant (charging period of 60 minutes, results indicate that a pacemaker utilizing this system can sustain operation for nearly 85 hours, without any noticeable side-effects or changes in temperature.

  13. Ultra-broadband indoor optical wireless communication system with multimode fiber.

    Science.gov (United States)

    Wang, Ke; Nirmalathas, Ampalavanapillai; Lim, Christina; Skafidas, Efstratios

    2012-05-01

    In this paper we experimentally demonstrate an ultra-broadband indoor full-duplex WDM optical wireless communication system with multimode fiber. The multimode fiber is used because it is employed in most of the already installed in-building fiber distribution networks. Simultaneous error-free (BER<10(-9)) transmission of 4×12.5 Gbps downlink and 800 Mbps uplink has been successfully demonstrated. The experimental results show that, although the use of multimode fiber will induce ~2.4 cm reduction in the maximum error-free beam footprint in the downlink, the bit rate of the uplink can be much higher compared to the system with single-mode fiber.

  14. Effective Linewidth of Semiconductor Lasers for Coherent Optical Data Links

    DEFF Research Database (Denmark)

    Iglesias Olmedo, Miguel; Pang, Xiaodan; Schatz, Richard

    2016-01-01

    We discuss the implications of using monolithically integrated semiconductor lasers in high capacity optical coherent links suitable for metro applications, where the integration capabilities of semiconductor lasers make them an attractive candidate to reduce transceiver cost. By investigating...... semiconductor laser frequency noise profiles we show that carrier induced frequency noise plays an important role in system performance. We point out that, when such lasers are employed, the commonly used laser linewidth fails to estimate system performance, and we propose an alternative figure of merit that we...... name “Effective Linewidth”. We derive this figure of merit analytically, explore it by numerical simulations and experimentally validate our results by transmitting a 28 Gbaud DP-16QAM over an optical link. Our investigations cover the use of semiconductor lasers both in the transmitter side...

  15. IEEE 802.3 Fiber Optic Inter-Repeater Link

    Science.gov (United States)

    Tarrant, Peter J.

    1987-01-01

    This paper describes the implementation of a fiber optic inter-repeater link (FOIRL), used for connecting two remote copper segments of an IEEE 802.3 local area network. The rationale for the design, the signalling used and the collision detection mechanism is discussed. The evolution of the draft international standard for the FOIRL and the concurrence amongst various manufacturers is also presented. Finally some examples of typical applications, highlighting the ease of installation, are given.

  16. Energy reduction using multi-channels optical wireless communication based OFDM

    Science.gov (United States)

    Darwesh, Laialy; Arnon, Shlomi

    2017-10-01

    In recent years, an increasing number of data center networks (DCNs) have been built to provide various cloud applications. Major challenges in the design of next generation DC networks include reduction of the energy consumption, high flexibility and scalability, high data rates, minimum latency and high cyber security. Use of optical wireless communication (OWC) to augment the DC network could help to confront some of these challenges. In this paper we present an OWC multi channels communication method that could lead to significant energy reduction of the communication equipment. The method is to convert a high speed serial data stream to many slower and parallel streams and vies versa at the receiver. We implement this concept of multi channels using optical orthogonal frequency division multiplexing (O-OFDM) method. In our scheme, we use asymmetrically clipped optical OFDM (ACO-OFDM). Our results show that the realization of multi channels OFDM (ACO-OFDM) methods reduces the total energy consumption exponentially, as the number of channels transmitted through them rises.

  17. Data security in high-speed optical links

    Science.gov (United States)

    Kartalopoulos, Stamatios V.

    2005-05-01

    Wavelength Division Multiplexing (WDM) is a photonic technology capable to transport over a single fiber more than a Tbit/s aggregate traffic. Currently, WDM is the only deployed method in transcontinental and transoceanic applications. In the optical network, each fiber link consists of segments, each several kilometers long, the connecting points of which are amenable to tapping. When a small amount of optical signal is extracted from a tap, when the signal is properly amplified it can be monitored by unauthorized personnel thus threatening communications and land-security. Since each WDM channel carries traffic from one customer, it is not difficult for the connoisseur to demultiplex a specific channel, isolate a specific payload and break the encrypted datagram. Therefore, in addition to data encryption, high-speed communications security should also rely on securing the optical links. In this paper, we present a WDM link security method that, even if fiber is tapped, constitutes channel monitoring and information decrypting by an eavesdropper or unauthorized personnel virtually impossible. In addition, we describe the circuit building blocks behind the method that makes eavesdropping impossible.

  18. High-speed digital fiber optic links for satellite traffic

    Science.gov (United States)

    Daryoush, A. S.; Ackerman, E.; Saedi, R.; Kunath, R. R.; Shalkhauser, K.

    1989-01-01

    Large aperture phased array antennas operating at millimeter wave frequencies are designed for space-based communications and imaging platforms. Array elements are comprised of active T/R modules which are linked to the central processing unit through high-speed fiber-optic networks. The system architecture satisfying system requirements at millimeter wave frequency is T/R level data mixing where data and frequency reference signals are distributed independently before mixing at the T/R modules. This paper demonstrates design procedures of a low loss high-speed fiber-optic link used for transmission of data signals over 600-900 MHz bandwidth inside satellite. The fiber-optic link is characterized for transmission of analog and digital data. A dynamic range of 79 dB/MHz was measured for analog data over the bandwidth. On the other hand, for bursted SMSK satellite traffic at 220 Mbps rates, BER of 2 x 10 to the -7th was measured for E(b)/N(o) of 14.3 dB.

  19. Characterization of In-Body to On-Body Wireless Radio Frequency Link for Upper Limb Prostheses.

    Directory of Open Access Journals (Sweden)

    Antonietta Stango

    Full Text Available Wireless implanted devices can be used to interface patients with disabilities with the aim of restoring impaired motor functions. Implanted devices that record and transmit electromyographic (EMG signals have been applied for the control of active prostheses. This simulation study investigates the propagation losses and the absorption rate of a wireless radio frequency link for in-to-on body communication in the medical implant communication service (MICS frequency band to control myoelectric upper limb prostheses. The implanted antenna is selected and a suitable external antenna is designed. The characterization of both antennas is done by numerical simulations. A heterogeneous 3D body model and a 3D electromagnetic solver have been used to model the path loss and to characterize the specific absorption rate (SAR. The path loss parameters were extracted and the SAR was characterized, verifying the compliance with the guideline limits. The path loss model has been also used for a preliminary link budget analysis to determine the feasibility of such system compliant with the IEEE 802.15.6 standard. The resulting link margin of 11 dB confirms the feasibility of the system proposed.

  20. Performance analysis of stationary Hadamard matrix diffusers in free-space optical communication links

    Science.gov (United States)

    Burrell, Derek J.; Middlebrook, Christopher T.

    2017-08-01

    Wireless communication systems that employ free-space optical links in place of radio/microwave technologies carry substantial benefits in terms of data throughput, network security and design efficiency. Along with these advantages comes the challenge of counteracting signal degradation caused by atmospheric turbulence in free-space environments. A fully coherent laser source experiences random phase delays along its traversing path in turbulent conditions forming a speckle pattern and lowering the received signal-to-noise ratio upon detection. Preliminary research has shown that receiver-side speckle contrast may be significantly reduced and signal-to-noise ratio increased accordingly through the use of a partially coherent light source. While dynamic diffusers and adaptive optics solutions have been proven effective, they also add expense and complexity to a system that relies on accessibility and robustness for successful implementation. A custom Hadamard diffractive matrix design is used to statically induce partial coherence in a transmitted beam to increase signal-to-noise ratio for experimental turbulence scenarios. Atmospheric phase screens are generated using an open-source software package and subsequently loaded into a spatial light modulator using nematic liquid crystals to modulate the phase.

  1. OPS: Opportunistic pipeline scheduling in long-strip wireless sensor networks with unreliable links

    NARCIS (Netherlands)

    Guo, Peng; Meratnia, Nirvana; Havinga, Paul J.M.; Jiang, He; Zhang, Kui

    2015-01-01

    Being deployed in narrow but long area, strip wireless sensor networks (SWSNs) have drawn much attention in applications such as coal mines, pipeline and structure monitoring. One of typical characteristics of SWSNs is the large hop counts, which leads to long end-to-end delivery delay in

  2. An Energy Efficient Adaptive Wireless Link for Farms based on IoT technologies

    DEFF Research Database (Denmark)

    Blaszczyk, Tomasz; Lynggaard, P.

    2015-01-01

    There is a huge demand for automation infrastructures that increase the efficiency and the commercial potential for the agricultural sector. One approach to achieve these objectives is deploying Internet of Things including its embedded wireless sensor network platform. However, deploying wireles...

  3. Scintillation analysis of multiple-input single-output underwater optical links.

    Science.gov (United States)

    Gökçe, Muhsİn Caner; Baykal, Yahya

    2016-08-01

    Multiple-input single-output (MISO) techniques are employed in underwater wireless optical communication (UWOC) links to mitigate the degrading effects of oceanic turbulence. In this paper, we consider a MISO UWOC system which consists of a laser beam array as transmitter and a point detector as receiver. Our aim is to find the scintillation index at the detector in order to quantify the system performance. For this purpose, the average intensity and the average of the square of the intensity are derived in underwater turbulence by using the extended Huygens-Fresnel principle. The scintillation index and the average bit-error-rate (⟨BER⟩) formulas presented in this paper depend on the oceanic turbulence parameters, such as the rate of dissipation of the mean-squared temperature, rate of dissipation of kinetic energy per unit mass of fluid, Kolmogorov microscale, and the ratio of temperature to salinity contributions to the refractive index spectrum, the link length, and the wavelength. Recently, we have derived an equivalent structure constant of atmospheric turbulence and expressed it in terms of the oceanic turbulence parameters [Appl. Opt.55, 1228 (2016)APOPAI0003-693510.1364/AO.55.001228]. In the formulation in this paper, this equivalent structure constant is utilized, which enables us to employ the existing similar formulation valid in atmospheric turbulence.

  4. International standards for optical wireless communications: state-of-the-art and future directions

    Science.gov (United States)

    Marciniak, Marian

    2017-10-01

    As the number of active OWC installations is growing fast, the standards for compatibility of co-existing neighbouring systems are being developed. The paper addresses the Laser Safety (IEC standards), ITU-T Study Group 15 standards (G.640 Co-location longitudinally compatible interfaces for free space optical systems), ITU-Radiocommunication Sector standards (P.1817-1 Propagation data required for the design of terrestrial free-space optical links), and the IEEE Work in Progress - standardization activity on Visible Light Communications. International standards of FSO communications have been reviewed and discussed. ITU, IEC, and IEEE International standards for Free-Space Optical links have been reviewed. The system reliability and availability as well as security issues will be addressed as well in the talk.

  5. Optical Switching for Dynamic Distribution of Wireless-Over-Fiber Signals in Active Optical Networks

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Rodes, Guillermo; Tafur Monroy, Idelfonso

    2012-01-01

    of a four wavelength-division-multiplexed channel system operating on a WiMax frequency band and employing an orthogonal-frequency-division-multiplexing modulation at 625 Mbits/s per channel, transmission of the data over 20 km of optical fiber, and active switching in a 1 × 16 active optical switch....... The results show a negligible power penalty on each channel for both the best and the worst case in terms of inter-channel crosstalk. The presented system is highly scalable both in terms of port count and throughput, a desirable feature in highly branched access networks, and is modulation- and frequency...

  6. The Effects of Weather on the Life Time of Wireless Sensor Networks Using FSO/RF Communication

    Directory of Open Access Journals (Sweden)

    F. Nadeem

    2010-06-01

    Full Text Available The increased interest in long lasting wireless sensor networks motivates to use Free Space Optics (FSO link along with radio frequency (RF link for communication. Earlier results show that RF/FSO wireless sensor networks have life time twice as long as RF only wireless sensor networks. However, for terrestrial applications, the effect of weather conditions such as fog, rain or snow on optical wireless communication link is major concern, that should be taken into account in the performance analysis. In this paper, life time performance of hybrid wireless sensor networks is compared to wireless sensor networks using RF only for terrestrial applications and weather effects of fog, rain and snow. The results show that combined hybrid network with three threshold scheme can provide efficient power consumption of 6548 seconds, 2118 seconds and 360 seconds for measured fog, snow and rain events respectively resulting in approximately twice of the life time with only RF link.

  7. Design and implementation of omni-directional light source and receiving system used in underwater wireless optical communication

    Science.gov (United States)

    Rao, Jionghui; Yao, Wenming; Chen, Nannan

    2013-08-01

    Underwater wireless optical communication is a communication mode which uses light as an information carrier and water as transmission medium. As a result of the inherent characteristics of the light waves, underwater wireless optical communication has the advantages of high transmission rate, good security, and strong anti-interference ability. It is suitable for high-speed, short-range communication between underwater mobile vehicles. Underwater optical wireless communication system designed in this paper is composed of the omni-directional communication light source and the receiving system. In the omni-directional communication light source, the laser beams with small divergence angle of 532nm wavelength produced by modulated laser are expanded through a combination refraction-reflection solid and then obtain more than 2π space divergence angle. The paper use TRACEPRO simulation tool to help design a combination solid composed of the lens, conical reflector and parabolic reflector, and test in the air and underwater, the result shows that the effect is fine. Unlike in the air, light attenuation is heavy in the water and a large range of variations in light intensity at different distances appear during underwater optical communication. In order to overcome this problem, the paper use a small photomultiplier as the detection device, design the receiving system using the automatic gain control technique. Underwater wireless optical communication system designed in this paper has the characteristics of small size, low power dissipation and the omni-directional communication function, it is suitable for application in the UUV, AUV, Swimmer Delivery Vehicle (SDV) and other underwater mobile platform, it realizes point-to-point communications and point-to-multipoint communications.

  8. Interoperation of an UHF RFID Reader and a TCP/IP Device via Wired and Wireless Links

    Directory of Open Access Journals (Sweden)

    Ik Soo Jin

    2011-11-01

    Full Text Available A main application in radio frequency identification (RFID sensor networks is the function that processes real-time tag information after gathering the required data from multiple RFID tags. The component technologies that contain an RFID reader, called the interrogator, which has a tag chip, processors, coupling antenna, and a power management system have advanced significantly over the last decade. This paper presents a system implementation for interoperation between an UHF RFID reader and a TCP/IP device that is used as a gateway. The proposed system consists of an UHF RFID tag, an UHF RFID reader, an RF end-device, an RF coordinator, and a TCP/IP I/F. The UHF RFID reader, operating at 915 MHz, is compatible with EPC Class-0/Gen1, Class-1/Gen1 and 2, and ISO18000-6B. In particular, the UHF RFID reader can be combined with the RF end-device/coordinator for a ZigBee (IEEE 802.15.4 interface, which is a low-power wireless standard. The TCP/IP device communicates with the RFID reader via wired links. On the other hand, it is connected to the ZigBee end-device via wireless links. The web based test results show that the developed system can remotely recognize information of multiple tags through the interoperation between the RFID reader and the TCP/IP device.

  9. Layered ACO-OFDM for intensity-modulated direct-detection optical wireless transmission.

    Science.gov (United States)

    Wang, Qi; Qian, Chen; Guo, Xuhan; Wang, Zhaocheng; Cunningham, David G; White, Ian H

    2015-05-04

    Layered asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) with high spectral efficiency is proposed in this paper for optical wireless transmission employing intensity modulation with direct detection. In contrast to the conventional ACO-OFDM, which only utilizes odd subcarriers for modulation, leading to an obvious spectral efficiency loss, in layered ACO-OFDM, the subcarriers are divided into different layers and modulated by different kinds of ACO-OFDM, which are combined for simultaneous transmission. In this way, more subcarriers are used for data transmission and the spectral efficiency is improved. An iterative receiver is also proposed for layered ACO-OFDM, where the negative clipping distortion of each layer is subtracted once it is detected so that the signals from different layers can be recovered. Theoretical analysis shows that the proposed scheme can improve the spectral efficiency by up to 2 times compared with conventional ACO-OFDM approaches with the same modulation order. Meanwhile, simulation results confirm a considerable signal-to-noise ratio gain over ACO-OFDM at the same spectral efficiency.

  10. Performance Analysis of DC-offset STBCs for MIMO Optical Wireless Communications

    KAUST Repository

    Sapenov, Yerzhan

    2017-04-01

    In this report, an optical wireless multiple-input multiple-output communication system employing intensity-modulation direct-detection is considered. The performance of direct current offset space-time block codes (DC-STBC) is studied in terms of pairwise error probability (PEP). It is shown that among the class of DC-STBCs, the worst case PEP corresponding to the minimum distance between two codewords is minimized by repetition coding (RC), under both electrical and optical individual power constraints. It follows that among all DC-STBCs, RC is optimal in terms of worst-case PEP for static channels and also for varying channels under any turbulence statistics. This result agrees with previously published numerical results showing the superiority of RC in such systems. It also agrees with previously published analytic results on this topic under log-normal turbulence and further extends it to arbitrary turbulence statistics. This shows the redundancy of the time-dimension of the DCSTBC in this system. This result is further extended to sum power constraints with static and turbulent channels, where it is also shown that the time dimension is redundant, and the optimal DC-STBC has a spatial beamforming structure. Numerical results are provided to demonstrate the difference in performance for systems with different numbers of receiving apertures and different throughput.

  11. Diversity-optimal power loading for intensity modulated MIMO optical wireless communications.

    Science.gov (United States)

    Zhang, Yan-Yu; Yu, Hong-Yi; Zhang, Jian-Kang; Zhu, Yi-Jun

    2016-04-18

    In this paper, we consider the design of space code for an intensity modulated direct detection multi-input-multi-output optical wireless communication (IM/DD MIMO-OWC) system, in which channel coefficients are independent and non-identically log-normal distributed, with variances and means known at the transmitter and channel state information available at the receiver. Utilizing the existing space code design criterion for IM/DD MIMO-OWC with a maximum likelihood (ML) detector, we design a diversity-optimal space code (DOSC) that maximizes both large-scale diversity and small-scale diversity gains and prove that the spatial repetition code (RC) with a diversity-optimized power allocation is diversity-optimal among all the high dimensional nonnegative space code schemes under a commonly used optical power constraint. In addition, we show that one of significant advantages of the DOSC is to allow low-complexity ML detection. Simulation results indicate that in high signal-to-noise ratio (SNR) regimes, our proposed DOSC significantly outperforms RC, which is the best space code currently available for such system.

  12. Fundamental Limits of Parallel Optical Wireless Channels: Capacity Results and Outage Formulation

    KAUST Repository

    Chaaban, Anas

    2016-10-26

    Multi-channel (MC) optical wireless communication (OWC) systems employing wave-division multiplexing for outdoors free-space optical communications, or multi-user timedivision multiple access for indoors visible-light communications, e.g., can be modeled as parallel channels. Multi-input multioutput OWC systems can also be transformed, possibly with some performance loss, to parallel channels using pre-/postcoding. Studying the performance of such MC-OWC systems requires characterizing the capacity of the underlying parallel channels. In this paper, upper and lower bounds on the capacity of constant parallel OWC channels with a total average intensity constraint are derived. Then, the paper focuses on finding intensity allocations that maximize the lower bounds given channel-state information at the transmitter (CSIT). Due to its nonconvexity, the KKT conditions are used to describe a list of candidate allocations. Instead searching exhaustively for the best solution, low-complexity near-optimal algorithms are proposed. The resulting optimized lower bound nearly coincides with capacity at high signal-to-noise ratio (SNR). Under a quasi-static channel model and in the absence of CSIT, outage probability upper and lower bounds are derived. Those bounds also meet at high SNR, thus characterizing the outage capacity in this regime. Finally, the results are extended to a system with both average and peak intensity constraints.

  13. Wired and wireless convergent extended-reach optical access network using direct-detection of all-optical OFDM super-channel signal.

    Science.gov (United States)

    Chow, C W; Yeh, C H; Sung, J Y; Hsu, C W

    2014-12-15

    We propose and demonstrate the feasibility of using all-optical orthogonal frequency division multiplexing (AO-OFDM) for the convergent optical wired and wireless access networks. AO-OFDM relies on all-optically generated orthogonal subcarriers; hence, high data rate (> 100 Gb/s) can be easily achieved without hitting the speed limit of electronic digital-to-analog and analog-to-digital converters (DAC/ADC). A proof-of-concept convergent access network using AO-OFDM super-channel (SC) is demonstrated supporting 40 - 100 Gb/s wired and gigabit/s 100 GHz millimeter-wave (MMW) ROF transmissions.

  14. Symmetric Link Key Management for Secure Neighbor Discovery in a Decentralized Wireless Sensor Network

    Science.gov (United States)

    2017-09-01

    DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words ) Wireless sensor networks provide a low-signature communications system that can be used for a... serve as the basis for our research. Then, we review existing research in key management for secure neighbor discovery. A. NEIGHBOR DISCOVERY...against Common Forms of Attack Our research served as a proof-of-concept for our key management scheme as applied to neighbor discovery; however, the

  15. A Power-Efficient Wireless Capacitor Charging System Through an Inductive Link

    OpenAIRE

    Lee, Hyung-Min; Ghovanloo, Maysam

    2013-01-01

    A power-efficient wireless capacitor charging system for inductively powered applications has been presented. A bank of capacitors can be directly charged from an ac source by generating a current through a series charge injection capacitor and a capacitor charger circuit. The fixed charging current reduces energy loss in switches, while maximizing the charging efficiency. An adaptive capacitor tuner compensates for the resonant capacitance variations during charging to keep the amplitude of ...

  16. Plastic optical fiber serial communications link for distributed control system

    Science.gov (United States)

    Saxena, Piyush; Sharangpani, K. K.; Vora, H. S.; Nakhe, S. V.; Jain, R.; Shenoy, N. M.; Bhatnagar, R.; Shirke, N. D.

    2001-09-01

    One of the most common interface for communications specified is RS 232C standard. Though widely accepted, RS232 has limited transmission speed, range and networking capabilities. RS 422 standard overcomes limitations by using differential signal lines. In automation of the operation of gas discharge lasers, multiple processors are used for control of lasers, cooling system, vacuum system etc. High EMI generated by lasers interfere through galvanic transmission or by radiation over the length of cables, and hang up operation of processors or control PC. A serial communications link was designed eliminating copper transmission media, using plastic optical fiber cables and components, to connect local controllers with the master PC working on RS232 protocols. The paper discusses the design and implementation of a high ly reliable EMI harden serial communications link.

  17. Optic Nerve Stimulation System with Adaptive Wireless Powering and Data Telemetry

    Directory of Open Access Journals (Sweden)

    Xing Li

    2017-12-01

    Full Text Available To treat retinal degenerative diseases, a transcorneal electrical stimulation-based system is proposed, which consists of an eye implant and an external component. The eye implant is wirelessly powered and controlled by the external component to generate the required bi-polar current pattern for transcorneal stimulation with an amplitude range of 5 μA to 320 μA, a frequency range of 10 Hz to 160 Hz and a duty ratio range of 2.5% to 20%. Power delivery control includes power boosting in preparation for stimulation, and normal power regulation that adapts to both coupling and load variations. Only one pair of coils is used for both the power link and the bi-directional data link. Except for the secondary coil, the eye implant is fully integrated on chip and is fabricated using UMC (United Microelectronics Corporation, Hsinchu, Taiwan 0.13 μm complementary metal-oxide-semiconductor (CMOS process with a size of 1.5 mm × 1.5 mm. The secondary coil is fabricated on a printed circuit board (PCB with a diameter of only 4.4 mm. After coating with biocompatible silicone, the whole implant has dimensions of 6 mm in diameter with a thickness of less than 1 mm. The whole device can be put onto the sclera and beneath the eye’s conjunctiva. System functionality and electrical performance are demonstrated with measurement results.

  18. Model of Atmospheric Links on Optical Communications from High Altitude

    Science.gov (United States)

    Subich, Christopher

    2004-01-01

    Optical communication links have the potential to solve many of the problems of current radio and microwave links to satellites and high-altitude aircraft. The higher frequency involved in optical systems allows for significantly greater signal bandwidth, and thus information transfer rate, in excess of 10 Gbps, and the highly directional nature of laser-based signals eliminates the need for frequency-division multiplexing seen in radio and microwave links today. The atmosphere, however, distorts an optical signal differently than a microwave signal. While the ionosphere is one of the most significant sources of noise and distortion in a microwave or radio signal, the lower atmosphere affects an optical signal more significantly. Refractive index fluctuations, primarily caused by changes in atmospheric temperature and density, distort the incoming signal in both deterministic and nondeterministic ways. Additionally, suspended particles, such as those in haze or rain, further corrupt the transmitted signal. To model many of the atmospheric effects on the propagating beam, we use simulations based on the beam-propagation method. This method, developed both for simulation of signals in waveguides and propagation in atmospheric turbulence, separates the propagation into a diffraction and refraction problem. The diffraction step is an exact solution, within the limits of numerical precision, to the problem of propagation in free space, and the refraction step models the refractive index variances over a segment of the propagation path. By applying refraction for a segment of the propagation path, then diffracting over that same segment, this method forms a good approximation to true propagation through the atmospheric medium. Iterating over small segments of the total propagation path gives a good approximation to the problem of propagation over the entire path. Parameters in this model, such as initial beam profile and atmospheric constants, are easily modified in a

  19. Monitoring Spacecraft Telemetry Via Optical or RF Link

    Science.gov (United States)

    Fielhauer, K. B.; Boone, B. G.

    2011-01-01

    A patent disclosure document discusses a photonic method for connecting a spacecraft with a launch vehicle upper-stage telemetry system as a means for monitoring a spacecraft fs health and status during and right after separation and deployment. This method also provides an efficient opto-coupled capability for prelaunch built-in-test (BIT) on the ground to enable more efficient and timely integration, preflight checkout, and a means to obviate any local EMI (electromagnetic interference) during integration and test. Additional utility can be envisioned for BIT on other platforms, such as the International Space Station (ISS). The photonic telemetry system implements an optical free-space link with a divergent laser transmitter beam spoiled over a significant cone angle to accommodate changes in spacecraft position without having to angle track it during deployment. Since the spacecraft may lose attitude control and tumble during deployment, the transmitted laser beam interrogates any one of several low-profile meso-scale retro-reflective spatial light modulators (SLMs) deployed over the surface of the spacecraft. The return signal beam, modulated by the SLMs, contains health, status, and attitude information received back at the launch vehicle. Very compact low-power opto-coupler technology already exists for the received signal (requiring relatively low bandwidths, e.g., .200 kbps) to enable transfer to a forward pass RF relay from the launch vehicle to TDRSS (Tracking and Data Relay Satellite System) or another recipient. The link would be active during separation and post-separation to monitor spacecraft health, status, attitude, or other data inventories until attitude recovery and ground control can be re-established. An optical link would not interfere with the existing upper stage telemetry and beacon systems, thus meeting launch vehicle EMI environmental constraints.

  20. BICM-ID with Physical Layer Network Coding in TWR Free Space Optical Communication Links

    Directory of Open Access Journals (Sweden)

    Alaa A. Saeed Al-Rubaie

    2017-07-01

    Full Text Available Physical layer network coding (PNC is a promising technique to improve the network throughput in a two-way relay (TWR channel for two users to exchange messages across a wireless network. The PNC technique incorporating a TWR channel is embraced by a free space optical (FSO communication link for full utilization of network resources, namely TWR-FSO PNC. In this paper, bit interleaved coded modulation with iterative decoding (BICM-ID is adopted to combat the deleterious effect of the turbulence channel by saving the message being transmitted to increase the reliability of the system. Moreover, based on this technique, comparative studies between end-to-end BICM-ID code, non-iterative convolutional coded and uncoded systems are carried out. Furthermore, this paper presents the extrinsic information transfer (ExIT charts to evaluate the performance of BICM-ID code combined with the TWR-FSO PNC system. The simulation results show that the proposed scheme can achieve a significant bit error rate (BER performance improvement through the introduction of an iterative process between a soft demapper and decoder. Similarly, Monte Carlo simulation results are provided to support the findings. Subsequently, the ExIT functions of the two receiver components are thoroughly analysed for a variety of parameters under the influence of a turbulence-induced channel fading, demonstrating the convergence behaviour of BICM-ID to enable the TWR-FSO PNC system, effectively mitigating the impact of the fading turbulence channel.

  1. Novel 2D-sequential color code system employing Image Sensor Communications for Optical Wireless Communications

    Directory of Open Access Journals (Sweden)

    Trang Nguyen

    2016-06-01

    Full Text Available The IEEE 802.15.7r1 Optical Wireless Communications Task Group (TG7r1, also known as the revision of the IEEE 802.15.7 Visible Light Communication standard targeting the commercial usage of visible light communication systems, is of interest in this paper. The paper is mainly concerned with Image Sensor Communications (ISC of TG7r1; however, the major challenge facing ISC, as addressed in the Technical Consideration Document (TCD of TG7r1, is Image Sensor Compatibility among the variety of different commercial cameras on the market. One of the most challenging but interesting compatibility requirements is the need to support the verified presence of frame rate variation. This paper proposes a novel design for 2D-sequential color code. Compared to a QR-code-based sequential transmission, the proposed design of 2D-sequential code can overcome the above challenge that it is compatible with different frame rate variations and different shutter operations, and has the ability to mitigate the rolling effect as well as the rotating effect while effectively minimizing transmission overhead. Practical implementations are demonstrated and a performance comparison is presented.

  2. Suboptimal maximum likelihood detection of on-off keying for a wireless optical communication system.

    Science.gov (United States)

    Li, Ruijie; Ding, Shengli; Dang, Anhong

    2017-05-01

    This paper investigates a detection scheme without channel state information for wireless optical communication systems. Employing conventional on-off keying signals, we supposed that conditional probability density function P(r|0) is much bigger than P(r|1) when r<0. Under this assumption, the suboptimal maximum likelihood scheme is obtained by utilizing the probability density function without channel information. Theoretical analysis shows the performance of the proposed scheme is close to the maximum likelihood symbol-by-symbol detection. Compared with the maximum likelihood symbol by symbol detection, Monte Carlo simulations show that the performance of the proposed scheme is about 0.62 dB loss for a gamma-gamma channel with a Rytov variance of 1 at the signal-to-noise ratio of 2 dB, but the efficient algorithm makes the real-time implementation of detection based on maximum likelihood feasible. Besides, the experiment is set up under 2 Gbps, and the experimental results match well with that of the theory and simulation.

  3. OFDM-based broadband underwater wireless optical communication system using a compact blue LED

    Science.gov (United States)

    Xu, Jing; Kong, Meiwei; Lin, Aobo; Song, Yuhang; Yu, Xiangyu; Qu, Fengzhong; Han, Jun; Deng, Ning

    2016-06-01

    We propose and experimentally demonstrate an IM/DD-OFDM-based underwater wireless optical communication system. We investigate the dependence of its BER performance on the training symbol number as well as LED's bias voltage and driving voltage. With single compact blue LED and a low-cost PIN photodiode, we achieve net bit rates of 225.90 Mb/s at a BER of 1.54×10-3 using 16-QAM and 231.95 Mb/s at a BER of 3.28×10-3 using 32-QAM, respectively, over a 2-m air channel. Over a 2-m underwater channel, we achieve net bit rates of 161.36 Mb/s using 16-QAM, 156.31 Mb/s using 32-QAM, and 127.07 Mb/s using 64-QAM, respectively. The corresponding BERs are 2.5×10-3, 7.42×10-4, and 3.17×10-3, respectively, which are all below the FEC threshold.

  4. Differential Amplitude Pulse-Position Modulation for Indoor Wireless Optical Communications

    Directory of Open Access Journals (Sweden)

    Sethakaset Ubolthip

    2005-01-01

    Full Text Available We propose a novel differential amplitude pulse-position modulation (DAPPM for indoor optical wireless communications. DAPPM yields advantages over PPM, DPPM, and DH-PIM in terms of bandwidth requirements, capacity, and peak-to-average power ratio (PAPR. The performance of a DAPPM system with an unequalized receiver is examined over nondispersive and dispersive channels. DAPPM can provide better bandwidth and/or power efficiency than PAM, PPM, DPPM, and DH-PIM depending on the number of amplitude levels and the maximum length of a symbol. We also show that, given the same maximum length, DAPPM has better bandwidth efficiency but requires about and more power than PPM and DPPM, respectively, at high bit rates over a dispersive channel. Conversely, DAPPM requires less power than DH-PIM . When the number of bits per symbol is the same, PAM requires more power, and DH-PIM less power, than DAPPM. Finally, it is shown that the performance of DAPPM can be improved with MLSD, chip-rate DFE, and multichip-rate DFE.

  5. Free Space Optics – Monitoring Setup for Experimental Link

    Directory of Open Access Journals (Sweden)

    Ján Tóth

    2015-12-01

    Full Text Available This paper deals with advanced Free Space Optics communication technology. Two FSO nodes are needed in order to make a connection. Laser diodes are used as light sources. Simple OOK modulation is involved in this technology. FSO system offers multiple advantages indeed. However, a direct visibility is required in order to set up a communication link. This fact yields perhaps the most significant weakness of this technology. Obviously, there is no a chance to fight the weather phenomena like fog, heavy rain, dust and many other particles which are naturally present in the atmosphere. That’s why there is a key task to find a suitable solution to keep FSO link working with high reliability and availability. It turns out that it’s necessary to have knowledge about weather situation when FSO link operates (liquid water content - LWC, geographical location, particle size distribution, average particle diameter, temperature, humidity, wind conditions, pressure and many other variable weather parameters. It’s obvious that having most of mentioned parameter’s values stored in database (implicitly in charts would be really beneficial. This paper presents some of mentioned indicators continuously gathered from several sensors located close to one of FSO nodes.

  6. A Regulation-Based Security Evaluation Method for Data Link in Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Claudio S. Malavenda

    2014-01-01

    Full Text Available This article presents a novel approach to the analysis of wireless sensor networks (WSN security, based on the regulations intended for wireless communication devices. Starting from the analysis and classification of attacks, countermeasures, and available protocols, we present the current state on secure communication stacks for embedded systems. The regulation analysis is based on civil EN 50150 and MIL STD-188-220, both applicable to WSN communications. Afterwards, starting from a list of known WSN attacks, we use a correspondence table to match WSN attacks with countermeasures required by regulations. This approach allows us to produce a precise security evaluation and classification methodology for WSN protocols. The results show that current protocols do not present a complete coverage of security issues. While this conclusion is already known for many WSN protocols, to the best of our knowledge this is the first time a complete methodology is proposed to base this assertion. Moreover, by using the proposed methodology, we are able to precisely identify the exposed threats for each WSN protocol under analysis.

  7. An Energy-Efficient Link Layer Protocol for Reliable Transmission over Wireless Networks

    Directory of Open Access Journals (Sweden)

    Iqbal Adnan

    2009-01-01

    Full Text Available In multihop wireless networks, hop-by-hop reliability is generally achieved through positive acknowledgments at the MAC layer. However, positive acknowledgments introduce significant energy inefficiencies on battery-constrained devices. This inefficiency becomes particularly significant on high error rate channels. We propose to reduce the energy consumption during retransmissions using a novel protocol that localizes bit-errors at the MAC layer. The proposed protocol, referred to as Selective Retransmission using Virtual Fragmentation (SRVF, requires simple modifications to the positive-ACK-based reliability mechanism but provides substantial improvements in energy efficiency. The main premise of the protocol is to localize bit-errors by performing partial checksums on disjoint parts or virtual fragments of a packet. In case of error, only the corrupted virtual fragments are retransmitted. We develop stochastic models of the Simple Positive-ACK-based reliability, the previously-proposed Packet Length Optimization (PLO protocol, and the SRVF protocol operating over an arbitrary-order Markov wireless channel. Our analytical models show that SRVF provides significant theoretical improvements in energy efficiency over existing protocols. We then use bit-error traces collected over different real networks to empirically compare the proposed and existing protocols. These experimental results further substantiate that SRVF provides considerably better energy efficiency than Simple Positive-ACK and Packet Length Optimization protocols.

  8. Wireless Device-to-Device (D2D) Links for Machine-to-Machine (M2M) Communication

    DEFF Research Database (Denmark)

    Pratas, Nuno; Popovski, Petar

    2017-01-01

    Device-to-Device (D2D) communications will play an important role in the fifth generation (5G) cellular networks, by increasing the spatial reuse of spectrum resources and enabling communication links with low latency. D2D is composed of two fundamental building blocks: proximity discovery...... and direct communication between nearby users. Another emerging trend in wireless cellular systems is Machine-to-Machine (M2M) communications, often characterized by fixed, low transmission rates. In this chapter we motivate the synergy between D2D and M2M, and present technologies that enable M2M-via-D2D...... communication to operate as an underlay to the ordinary cellular transmissions....

  9. Prediction and comparison of down-link electric field and uplink localised SAR values for realistic indoor wireless planning

    International Nuclear Information System (INIS)

    Plets, David; Joseph, Wout; Aerts, Sam; Vanhecke, Kris; Vermeeren, Guenter; Martens, Luc

    2014-01-01

    In this paper, for the first time a heuristic network calculator for both whole-body exposure due to indoor base station antennas or access points (down-link exposure) and localised exposure due to the mobile device (uplink exposure) in indoor wireless networks is presented. As an application, three phone call scenarios are investigated (Universal Mobile Telecommunications System (UMTS) macro-cell, UMTS femto-cell and WiFi voice-over-IP) and compared with respect to the electric-field strength and localised specific absorption rate (SAR) distribution. Prediction models are created and successfully validated with an accuracy of 3 dB. The benefits of the UMTS power control mechanisms are demonstrated. However, dependent on the macro-cell connection quality and on the user's average phone call connection time, also the macro-cell solution might be preferential from an exposure point of view for the considered scenario. (authors)

  10. Maximization of imaging resolution in optical wireless sensor/lab-on-chip/SoC networks with solar cells.

    Science.gov (United States)

    Arnon, Shlomi

    2010-09-01

    The availability of sophisticated and low-cost hardware on a single chip, for example, CMOS cameras, CPU, DSP, processors and communication transceivers, optics, microfluidics, and micromechanics, has fostered the development of system-on-chip (SoC) technology, such as lab-on-chip or wireless multimedia sensor networks (WMSNs). WMSNs are networks of wirelessly interconnected devices on a chip that are able to ubiquitously retrieve multimedia content such as video from the environment and transfer it to a central location for additional processing. In this paper, we study WMSNs that include an optical wireless communication transceiver that uses light to transmit the information. One of the primary challenges in SoC design is to attain adequate resources like energy harvesting using solar cells in addition to imaging and communication capabilities, all within stringent spatial limitations while maximizing system performances. There is an inevitable trade-off between enhancing the imaging resolution and the expense of reducing communication capacity and energy harvesting capabilities, on one hand, and increasing the communication or the solar cell size to the detriment of the imaging resolution, on the other hand. We study these trade-offs, derive a mathematical model to maximize the resolution of the imaging system, and present a numerical example that demonstrates maximum imaging resolution. Our results indicate that an eighth-order polynomial with only two constants provides the required area allocation between the different functionalities.

  11. An Interference-Aware Traffic-Priority-Based Link Scheduling Algorithm for Interference Mitigation in Multiple Wireless Body Area Networks

    Directory of Open Access Journals (Sweden)

    Thien T. T. Le

    2016-12-01

    Full Text Available Currently, wireless body area networks (WBANs are effectively used for health monitoring services. However, in cases where WBANs are densely deployed, interference among WBANs can cause serious degradation of network performance and reliability. Inter-WBAN interference can be reduced by scheduling the communication links of interfering WBANs. In this paper, we propose an interference-aware traffic-priority-based link scheduling (ITLS algorithm to overcome inter-WBAN interference in densely deployed WBANs. First, we model a network with multiple WBANs as an interference graph where node-level interference and traffic priority are taken into account. Second, we formulate link scheduling for multiple WBANs as an optimization model where the objective is to maximize the throughput of the entire network while ensuring the traffic priority of sensor nodes. Finally, we propose the ITLS algorithm for multiple WBANs on the basis of the optimization model. High spatial reuse is also achieved in the proposed ITLS algorithm. The proposed ITLS achieves high spatial reuse while considering traffic priority, packet length, and the number of interfered sensor nodes. Our simulation results show that the proposed ITLS significantly increases spatial reuse and network throughput with lower delay by mitigating inter-WBAN interference.

  12. Hybrid Radio Frequency/Free-Space Optics (RF/FSO) Wireless Sensor Network: Security Concerns and Protective Measures

    Science.gov (United States)

    Banerjee, Koushik; Sharma, Hemant; Sengupta, Anasuya

    Wireless sensor networks (WSNs) are ad hoc wireless networks that are written off as spread out structure and ad hoc deployment. Sensor networks have all the rudimentary features of ad hoc networks but to altered points—for instance, considerably lesser movement and far more energy necessities. Commonly used technology for communication is radio frequency (RF) communications. Free-space optics (FSO) is relatively new technology which has the prospective to deliver remarkable increases in network lifetime of WSN. Hybrid RF/FSO communications has been suggested to decrease power consumption by a single sensor node. It is observed that security plays a very important role for either RF WSN or hybrid RF/FSO WSN as those are vulnerable to numerous threats. In this paper, various possible attacks in RF/FSO WSN are discussed and aimed to propose some way out from those attacks.

  13. The Gigabit Link Interface Board (GLIB), a flexible system for the evaluation and use of GBT-based optical links

    CERN Document Server

    Vichoudis, P; Vasey, F; Joos, M; Hansen, M; Haas, S; Baron, S

    2010-01-01

    The Gigabit Link Interface Board (GLIB) is an evaluation platform and an easy entry point for users of high speed optical links in high energy physics experiments. Its intended use ranges from optical link evaluation in the laboratory to control, triggering and data acquisition from remote modules in beam or irradiation tests. The GLIB is an FPGA-based Advanced Mezzanine Card (AMC) conceived to serve a small and simple system residing either inside a Micro Telecommunications Computing Architecture (mu TCA) crate, or on a bench with a link to a PC. This paper presents the architecture of the GLIB, its features as well as examples of its use in different setups.

  14. Integrated Vivaldi plasmonic antenna for wireless on-chip optical communications.

    Science.gov (United States)

    Bellanca, Gaetano; Calò, Giovanna; Kaplan, Ali Emre; Bassi, Paolo; Petruzzelli, Vincenzo

    2017-07-10

    In this paper we propose a novel hybrid optical plasmonic Vivaldi antenna for operation in the standard C telecommunication band for wavelengths in the 1550 nm range. The antenna is fed by a silicon waveguide and is designed to have high gain and large bandwidth. The shape of the radiation pattern, with a main lobe along the antenna axis, makes this antenna suitable for point-to-point connections for inter- or intra-chip optical communications. Direct port-to-port short links for different connection distances and in a homogeneous environment have also been simulated to verify, by comparing the results of a full-wave simulation with the Friis transmission equation, the correctness of the antenna parameters obtained via near-to-far field transformation.

  15. Converged Wireless and Wireline Access System Based on Optical Phase Modulation for Both Radio-Over-Fiber and Baseband Signals

    DEFF Research Database (Denmark)

    Yu, Xianbin; Jensen, Jesper Bevensee; Zibar, Darko

    2008-01-01

    -to-zero differential quaternary phase-shift keyed signal and a 5.25-GHz RoF carrying 1.25 Gb/s, enables the use of identical optical receiver structures. The experimental results show that both receivers achieve error-free operation after 80-km standard single-mode fiber transmission. The proposed scheme has potential......We propose and experimentally investigate a scheme for transmitting a phase-modulated radio-over-fiber (RoF) signal along an existing fiber infrastructure without degradation of the existing baseband signal. Optical phase encoding of both signals, namely a baseband 21.4-Gb/s nonreturn...... applications for converged wireless and wireline optical access networks....

  16. Optical Interconnects for Smart Antenna Driver-Receiver-Switch System for Wireless Communication

    National Research Council Canada - National Science Library

    Esener, Sadik

    2002-01-01

    ... at 0.3THz-30THz for telecommunication applications in general and for interconnects within the box, in particular, for example for Smart Antenna Driver-Receiver-Switch System for Wireless Communication...

  17. Conclusions of ESA 1st Optical Wireless Onboard Communications Workshop: Current Status and the Road Forward

    National Research Council Canada - National Science Library

    Hernandez, Inmaculada; Plancke, Patrick

    2005-01-01

    The purpose of this workshop was to bring together representatives of European space agencies, aerospace industry, wireless technology industry, academia, research institutions, and end-users to do the following: (1...

  18. 30 pJ/b, 67 Mbps, Centimeter-to-Meter Range Data Telemetry With an IR-UWB Wireless Link.

    Science.gov (United States)

    Ebrazeh, Ali; Mohseni, Pedram

    2015-06-01

    This paper reports an energy-efficient, impulse radio ultra wideband (IR-UWB) wireless link operating in 3-5 GHz for data telemetry over centimeter-to-meter range distances at rates extended to tens of Mbps. The link comprises an all-digital, integrated transmitter (TX) fabricated in 90 nm 1P/9M CMOS that incorporates a waveform-synthesis pulse generator and a timing generator for on-off-keying (OOK) pulse modulation and phase scrambling. The link also incorporates an energy-detection receiver (RX) realized with commercial off-the-shelf (COTS) components that performs radio-frequency (RF) filtering, amplification, logarithmic power detection for data demodulation and automatic level control for robust operation in the presence of distance variations. Employing a miniaturized, UWB, chip antenna for the TX and RX, wireless transmission of pseudo-random binary sequence (PRBS) data at rates up to 50 Mbps over 10 cm-1 m is shown. Further, employing a high-gain horn antenna for the RX, wireless transmission of PRBS data at rates up to 67 Mbps over 50 cm-4 m is shown with a TX energy consumption of 30 pJ/b (i.e., power consumption of 2 mW) from 1.2 V. The measured bit error rate (BER) in both cases is UWB link are also included, exhibiting excellent match with those obtained from a conventional frequency-shift-keyed (FSK) link at ~433 MHz.

  19. Characterization of Industrial Coolant Fluids and Continuous Ageing Monitoring by Wireless Node-Enabled Fiber Optic Sensors.

    Science.gov (United States)

    Sachat, Alexandros El; Meristoudi, Anastasia; Markos, Christos; Sakellariou, Andreas; Papadopoulos, Aggelos; Katsikas, Serafim; Riziotis, Christos

    2017-03-11

    Environmentally robust chemical sensors for monitoring industrial processes or infrastructures are lately becoming important devices in industry. Low complexity and wireless enabled characteristics can offer the required flexibility for sensor deployment in adaptable sensing networks for continuous monitoring and management of industrial assets. Here are presented the design, development and operation of a class of low cost photonic sensors for monitoring the ageing process and the operational characteristics of coolant fluids used in an industrial heavy machinery infrastructure. The chemical, physical and spectroscopic characteristics of specific industrial-grade coolant fluids were analyzed along their entire life cycle range, and proper parameters for their efficient monitoring were identified. Based on multimode polymer or silica optical fibers, wide range (3-11) pH sensors were developed by employing sol-gel derived pH sensitive coatings. The performances of the developed sensors were characterized and compared, towards their coolants' ageing monitoring capability, proving their efficiency in such a demanding application scenario and harsh industrial environment. The operating characteristics of this type of sensors allowed their integration in an autonomous wireless sensing node, thus enabling the future use of the demonstrated platform in wireless sensor networks for a variety of industrial and environmental monitoring applications.

  20. Optical power allocation for adaptive transmissions in wavelength-division multiplexing free space optical networks

    Directory of Open Access Journals (Sweden)

    Hui Zhou

    2015-08-01

    Full Text Available Attracting increasing attention in recent years, the Free Space Optics (FSO technology has been recognized as a cost-effective wireless access technology for multi-Gigabit rate wireless networks. Radio on Free Space Optics (RoFSO provides a new approach to support various bandwidth-intensive wireless services in an optical wireless link. In an RoFSO system using wavelength-division multiplexing (WDM, it is possible to concurrently transmit multiple data streams consisting of various wireless services at very high rate. In this paper, we investigate the problem of optical power allocation under power budget and eye safety constraints for adaptive WDM transmission in RoFSO networks. We develop power allocation schemes for adaptive WDM transmissions to combat the effect of weather turbulence on RoFSO links. Simulation results show that WDM RoFSO can support high data rates even over long distance or under bad weather conditions with an adequate system design.

  1. Atmosphere characterization for simulation of the two optimal wireless terahertz digital communication links.

    Science.gov (United States)

    Mandehgar, Mahboubeh; Yang, Yihong; Grischkowsky, D

    2013-09-01

    Our studies of terahertz pulse propagation in the atmosphere have identified the two most optimal communication channels. The potential of these channels is demonstrated by physically accurate linear dispersion theory calculations of digital pulse propagation, showing it is possible to have two high-performance, point-to-point digital terahertz links in the atmosphere: a direct 95 GHz, 20 km ground link at 9.5 Gb/s with power loss of 10 dB due to water vapor at RH 58% (10 g/m3) and 20°C, and a direct 250 GHz, geosynchronous satellite link at 20.8 Gb/s with a 2 km zenith path with water vapor loss of 9 dB.

  2. Hybrid Polling Method for Direct Link Communication for IEEE 802.11 Wireless LANs

    Directory of Open Access Journals (Sweden)

    Woo-Yong Choi

    2008-10-01

    Full Text Available The direct link communication between STAtions (STAs is one of the techniques to improve the MAC performance of IEEE 802.11 infrastructure networks. For the efficient direct link communication, in the literature, the simultaneous polling method was proposed to allow the multiple direct data communication to be performed simultaneously. However, the efficiency of the simultaneous polling method is affected by the interference condition. To alleviate the problem of the lower polling efficiency with the larger interference range, the hybrid polling method is proposed for the direct link communication between STAs in IEEE 802.11 infrastructure networks. By the proposed polling method, we can integrate the sequential and simultaneous polling methods properly according to the interference condition. Numerical examples are also presented to show the medium access control (MAC performance improvement by the proposed polling method.

  3. Manchester encoder-decoder for optical data communication links.

    Science.gov (United States)

    Al-Sammak, A J; Al-Ruwaihi, K; Al-Kooheji, I

    1992-04-20

    A new encoder-decoder (CODEC) design of a Manchester coding scheme suitable for optical data communication links is presented. The design is simple and uses off-the-shelf digital electronic components and subsystems. The CODEC can be used for high data rate transmissions, typical of opticalfiber systems and local area networks. The decoder is insensitive to variations in the clock rates within the range of +/-33%, whereas the encoder, which is a simple XOR logic gate, is not affected by clock variations. During high-frequency operation (e.g., at 100 MHz), the CODEC can be operated at a wide range of frequencies (from 66.6 to 133.3 MHz) without modification to the CODEC circuitry. Furthermore, the CODEC can be made to operate at any data rate by a simple change of a single capacitor or a single resistor in the decoder circuit. The CODEC was built in the laboratory by using transistor-transistor logicintegrated circuits. It was experimentally found that with this decoder the transmitted data, as well as the cloc, can be recovered from the Manchester coded signal without being affected by clock variations within the designed range.

  4. On the power and offset allocation for rate adaptation of spatial multiplexing in optical wireless MIMO channels

    KAUST Repository

    Park, Kihong

    2013-04-01

    In this paper, we consider resource allocation method in the visible light communication. It is challenging to achieve high data rate due to the limited bandwidth of the optical sources. In order to increase the spectral efficiency, we design a suitable multiple-input multiple-output (MIMO) system utilizing spatial multiplexing based on singular value decomposition and adaptive modulation. More specifically, after explaining why the conventional allocation method in radio frequency MIMO channels cannot be applied directly to the optical intensity channels, we theoretically derive a power allocation method for an arbitrary number of transmit and receive antennas for optical wireless MIMO systems. Based on three key constraints: the nonnegativity of the intensity-modulated signal, the aggregate optical power budget, and the bit error rate requirement, we propose a novel method to allocate the optical power, the offset value, and the modulation size. Based on some selected simulation results, we show that our proposed allocation method gives a better spectral efficiency at the expense of an increased computational complexity in comparison to a simple method that allocates the optical power equally among all the data streams. © 2013 IEEE.

  5. Effect of soil temperature on optical frequency transfer through unidirectional dense-wavelength-division-multiplexing fiber-optic links.

    Science.gov (United States)

    Pinkert, T J; Böll, O; Willmann, L; Jansen, G S M; Dijck, E A; Groeneveld, B G H M; Smets, R; Bosveld, F C; Ubachs, W; Jungmann, K; Eikema, K S E; Koelemeij, J C J

    2015-02-01

    Results of optical frequency transfer over a carrier-grade dense-wavelength-division-multiplexing (DWDM) optical fiber network are presented. The relation between soil temperature changes on a buried optical fiber and frequency changes of an optical carrier through the fiber is modeled. Soil temperatures, measured at various depths by the Royal Netherlands Meteorology Institute (KNMI) are compared with observed frequency variations through this model. A comparison of a nine-day record of optical frequency measurements through the 2×298  km fiber link with soil temperature data shows qualitative agreement. A soil temperature model is used to predict the link stability over longer periods (days-months-years). We show that optical frequency dissemination is sufficiently stable to distribute and compare, e.g., rubidium frequency standards over standard DWDM optical fiber networks using unidirectional fibers.

  6. Real-Time Video Transmission Over Different Underwater Wireless Optical Channels Using a Directly Modulated 520  nm Laser Diode

    KAUST Repository

    Al-Halafi, Abdullah

    2017-09-13

    We experimentally demonstrate high-quality real-time video streaming over an underwater wireless optical communication (UWOC) link up to 5 m distance using phase-shift keying (PSK) modulation and quadrature amplitude modulation (QAM) schemes. The communication system uses software defined platforms connected to a commercial TO-9 packaged pigtailed 520 nm directly modulated laser diode (LD) with 1.2 GHz bandwidth as the optical transmitter and an avalanche photodiode (APD) module as the receiver. To simulate various underwater channels, we perform laboratory experiments on clear, coastal, harbor I, and harbor II ocean water types. The measured bit error rates of the received video streams are 1.0×10−9 for QPSK, 4-QAM, and 8-QAM and 9.9×10−9 for 8-PSK. We further evaluate the quality of the received live video images using structural similarity and achieve values of about 0.9 for the first three water types, and about 0.7 for harbor II. To the best of our knowledge, these results present the highest quality video streaming ever achieved in UWOC systems that resemble communication channels in real ocean water environments.

  7. Modeling the video distribution link in the Next Generation Optical Access Networks

    DEFF Research Database (Denmark)

    Amaya, F.; Cárdenas, A.; Tafur Monroy, Idelfonso

    2011-01-01

    In this work we present a model for the design and optimization of the video distribution link in the next generation optical access network. We analyze the video distribution performance in a SCM-WDM link, including the noise, the distortion and the fiber optic nonlinearities. Additionally, we...

  8. Radio over fiber for wireless communications from fundamentals to advanced topics

    CERN Document Server

    Fernando, Xavier N

    2014-01-01

    A comprehensive evaluation of Fi-Wi,  enabling readers to design links using channel estimation and equalization algorithms  This book provides a detailed study of radio over fiber (ROF) based wireless communication systems, otherwise called fiber wireless (Fi-Wi) systems. This is an emerging hot topic where the abundant bandwidth of optical fiber is directly combined with the flexibility and mobility of wireless networks to provide broadband connectivity.  Its application is increasing because of the growing demand for broadband wireless services. In such a system the transmission of the ra

  9. Cascaded multiplexed optical link on a telecommunication network for frequency dissemination.

    Science.gov (United States)

    Lopez, Olivier; Haboucha, Adil; Kéfélian, Fabien; Jiang, Haifeng; Chanteau, Bruno; Roncin, Vincent; Chardonnet, Christian; Amy-Klein, Anne; Santarelli, Giorgio

    2010-08-02

    We demonstrate a cascaded optical link for ultrastable frequency dissemination comprised of two compensated links of 150 km and a repeater station. Each link includes 114 km of Internet fiber simultaneously carrying data traffic through a dense wavelength division multiplexing technology, and passes through two routing centers of the telecommunication network. The optical reference signal is inserted in and extracted from the communication network using bidirectional optical add-drop multiplexers. The repeater station operates autonomously ensuring noise compensation on the two links and the ultra-stable signal optical regeneration. The compensated link shows a fractional frequency instability of 3 x 10(-15) at one second measurement time and 5 x 10(-20) at 20 hours. This work paves the way to a wide dissemination of ultra-stable optical clock signals between distant laboratories via the Internet network.

  10. A novel modulation scheme for noise reduction in analog fiber optic links

    NARCIS (Netherlands)

    Marpaung, D.A.I.; Roeloffzen, C.G.H.; van Etten, Wim

    2006-01-01

    A novel noise reduction scheme called Balanced Modulation and Detection (BMD) is proposed. In this scheme, the modulating RF signal is half-wave rectified in the optical domain, eliminating the DC optical power resulting from pre-biasing of the optical source. A link model employing this scheme has

  11. Radiation tolerant optical links for the readout of the ATLAS experiment

    CERN Document Server

    Pearce, M

    2000-01-01

    The ATLAS experiment will use radiation tolerant optical links to transfer data to and from sub-detector systems. The link specifications can be broadly divided into two classes, represented by the inner tracking detectors and the electromagnetic calorimeter. A feature common to all the readout links is the use of vertical cavity surface emitting laser diodes coupled to multimode optical fibres. Results from the development for both of these environments are reviewed with particular attention bring paid to irradiation studies. (8 refs).

  12. A High-Temporal and Spatial Resolution Soil Moisture and Soil Temperature Network In Iowa Using Wireless Links

    Science.gov (United States)

    Niemeier, J. J.; Kruger, A.; Krajewki, W. F.; Eichinger, W. E.; Hornbuckle, B. K.; Cunha, L.

    2007-12-01

    Over the past year we have created an in-situ soil moisture and soil temperature network in a 200 acre agricultural plot at Ames, Iowa. This work is part of a collaborative effort between researchers at The University of Iowa, and Iowa State University. The purpose of the network is to provide high temporal and spatial resolution soil moisture and soil temperature data to validate remotely-sensed observations of the terrestrial water cycle. This is part of a larger effort by the authors and collaborators to improve the quantitative value of remotely-sensed observations of the water cycle. In addition to the soil moisture and soil temperature measurements, detailed precipitation data, and atmospheric data such as air temperature, humidity, pressure, wind direction and velocity, and solar radiation data are collected. The current soil moisture network consists of 10 Iowa and Iowa State stations, each equipped with seven pairs of soil moisture and soil temperature sensors. In the future, the network will be expanded to 15 stations. At each of the 10 station the sensors pairs are deployed at depths of 1.5, 4.5, 15, 30, and 60 cm to provide a vertical profile of soil moisture and soil temperature. Prior to installation we calibrated the soil temperature sensors to within 0.1 degree Celsius. The time-domain reflectometry soil moisture measurements are adjusted for local soil conditions. At each of the 10 stations, data are collected every 10 minutes. The data are transmitted wirelessly with low power radio links to a central location. The system started collecting data at the beginning of July, 2007. One of the challenges we faced is how to provide reliable solar power to the wireless nodes, since the current crop, corn, grows up to 3 m tall, and casts dense shadows. The corn also significantly attenuates the radios signals, and the radios fell far short of their advertized ranges. Consequently, we had to use high-gain antennas, and robust retransmit communication modes

  13. Energy-Aware Topology Evolution Model with Link and Node Deletion in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Xiaojuan Luo

    2012-01-01

    Full Text Available Based on the complex network theory, a new topological evolving model is proposed. In the evolution of the topology of sensor networks, the energy-aware mechanism is taken into account, and the phenomenon of change of the link and node in the network is discussed. Theoretical analysis and numerical simulation are conducted to explore the topology characteristics and network performance with different node energy distribution. We find that node energy distribution has the weak effect on the degree distribution P(k that evolves into the scale-free state, nodes with more energy carry more connections, and degree correlation is nontrivial disassortative. Moreover, the results show that, when nodes energy is more heterogeneous, the network is better clustered and enjoys higher performance in terms of the network efficiency and the average path length for transmitting data.

  14. Hybrid Strategies for Link Adaptation Exploiting Several Degrees of Freedom in OFDM Based Broadband Wireless Systems

    DEFF Research Database (Denmark)

    Das, Suvra S.; Rahman, Muhammad Imadur; Wang, Yuanye

    2007-01-01

    In orthogonal frequency division multiplexing (OFDM) systems, there are several degrees of freedom in time and frequency domain, such as, sub-band size, forward error control coding (FEC) rate, modulation order, power level, modulation adaptation interval, coding rate adaptation interval and powe...... of the link parameters based on the channel conditions would lead to highly complex systems with high overhead. Hybrid strategies to vary the adaptation rates to tradeoff achievable efficiency and complexity are presented in this work.......In orthogonal frequency division multiplexing (OFDM) systems, there are several degrees of freedom in time and frequency domain, such as, sub-band size, forward error control coding (FEC) rate, modulation order, power level, modulation adaptation interval, coding rate adaptation interval and power...

  15. Two-user opportunistic scheduling using hierarchical modulations in wireless networks with heterogenous average link gains

    KAUST Repository

    Hossain, Md Jahangir

    2010-03-01

    Our contribution, in this paper, is two-fold. First, we analyze the performance of a hierarchical modulation-assisted two-best user opportunistic scheduling (TBS) scheme, which was proposed by the authors, in a fading environment where different users have different average link gains. Specifically, we present a new expression for the spectral efficiency (SE) of the users and using this expression, we compare the degrees of fairness (DOF) of the TBS scheme with that of classical single user opportunistic scheduling schemes, namely, absolute carrier-to-noise ratio (CNR) based single-best user scheduling (SBS) and normalized CNR based proportional fair scheduling (PFS) schemes. The second contribution is that we propose a new hybrid two-user opportunistic scheduling (HTS) scheme based on our earlier proposed TBS scheme. This HTS scheme selects the first user based on the largest absolute CNR value among all the users while the second user is selected based on the ratios of the absolute CNRs to the corresponding average CNRs of the remaining users. The total transmission rate i.e., the constellation size is selected according to the absolute CNR of the first best user. The total transmission rate is then allocated among these selected users by joint consideration of their absolute CNRs and allocated number of information bit(s) are transmitted to them using hierarchical modulations. Numerical results are presented for a fading environment where different users experience independent but non-identical (i.n.d.) channel fading. These selected numerical results show that the proposed HTS scheme can considerably increase the system\\'s fairness without any degradation of the link spectral efficiency (LSE) i.e., the multiuser diversity gain compared to the classical SBS scheme. These results also show that the proposed HTS scheme has a lower fairness in comparison to the PFS scheme which suffers from a considerable degradation in LSE. © 2010 IEEE.

  16. Applications of Emerging Parallel Optical Link Technology to High Energy Physics Experiments

    International Nuclear Information System (INIS)

    Chramowicz, J.; Kwan, S.; Prosser, A.; Winchell, M.

    2011-01-01

    Modern particle detectors depend upon optical fiber links to deliver event data to upstream trigger and data processing systems. Future detector systems can benefit from the development of dense arrangements of high speed optical links emerging from the telecommunications and storage area network market segments. These links support data transfers in each direction at rates up to 120 Gbps in packages that minimize or even eliminate edge connector requirements. Emerging products include a class of devices known as optical engines which permit assembly of the optical transceivers in close proximity to the electrical interfaces of ASICs and FPGAs which handle the data in parallel electrical format. Such assemblies will reduce required printed circuit board area and minimize electromagnetic interference and susceptibility. We will present test results of some of these parallel components and report on the development of pluggable FPGA Mezzanine Cards equipped with optical engines to provide to collaborators on the Versatile Link Common Project for the HI-LHC at CERN.

  17. Experimental Performance Comparison of 60 GHz DCM OFDM and Impulse BPSK Ultra-Wideband with Combined Optical Fibre and Wireless Transmission

    DEFF Research Database (Denmark)

    Beltrán, Marta; Jensen, Jesper Bevensee; Yu, Xianbin

    2010-01-01

    We present an experimental performance comparison of 1.44Gbps dual-carrier modulation OFDM and BPSK impulse-radio ultra-wideband in the 60GHz band with combined fibre, up to 40km, and 5m wireless transmission. Impulse-radio exhibits better dispersion tolerance requiring lower optical power....

  18. Convergencia de sistemas de comunicación ópticos e inalámbricos (Converged wireless and optical communication systems)

    DEFF Research Database (Denmark)

    Tafur Monroy, Idelfonso; Guerrero Gonzalez, Neil; Caballero Jambrina, Antonio

    2009-01-01

    Users of tele-information services are demanding instant access, everywhere and anytime. Wireless communication systems offers mobility and flexibility while optical fiber based systems offer large bandwidth, secure and lower power consumption for transport of tele-communication signals. None of ...

  19. Power Budget Analysis of Fiber Optics Communication Links Along ...

    African Journals Online (AJOL)

    With the development of optical fiber communication system most telecommunication companies now prefer to use optical fiber transmission medium for higher information bandwidth. The design of such a system involves many aspects such as the type of source to be used, the kind of fiber to be employed and detector.

  20. Analysis of the performance of a wireless optical multi-input to multi-output communication system.

    Science.gov (United States)

    Bushuev, Denis; Arnon, Shlomi

    2006-07-01

    We investigate robust optical wireless communication in a highly scattering propagation medium using multielement optical detector arrays. The communication setup consists of synchronized multiple transmitters that send information to a receiver array and an atmospheric propagation channel. The mathematical model that best describes this scenario is multi-input to multi-output communication through stochastic slow changing channels. In this model, signals from m transmitters are received by n receiver-detectors. The channel transfer function matrix is G, and its size is n x m. G(i,j) is the transfer function from transmitter i to detector j, and m > or = n. We adopt a quasi-stationary approach in which the channel time variation has a negligible effect on communication performance over a burst. The G matrix is calculated on the basis of the optical transfer function of the atmospheric channel (composed of aerosol and turbulence elements) and the receiver's optics. In this work we derive a performance model using environmental data, such as documented turbulence and aerosol models and noise statistics. We also present the results of simulations conducted for the proposed detection algorithm.

  1. Data transmission optical link for RF-GUN project

    Science.gov (United States)

    Olowski, Krzysztof; Zielinski, Jerzy; Jalmuzna, Wojciech; Pozniak, Krzysztof; Romaniuk, Ryszard

    2005-09-01

    Today, the fast optical data transmission is one of the fundamentals of modern distributed control systems. The fibers are widely use as multi-gigabit data stream medium. For a short range transmission, the multimode fibers are in common use. The data rate for this kind of transmission exceeds 10 Gbps for 10 Gigabit Ethernet and 10G Fibre Channel protocols. The Field Programmable Gate Arrays are one of the opportunities of managing the optical transmission. This article is concerning a synchronous optical transmission system via a multimode fiber. The transmission is controlled by the FPGA of two manufacturers: Xilinx and Altera. This paper contains the newest technology overview and market device parameters. It also describes a board for the optical transmission, technical details of the transmission and optical transmission results.

  2. Gigabit close-proximity wireless connections supported by 60 GHz RoF links with low carrier suppression

    DEFF Research Database (Denmark)

    Lebedev, Alexander; Pang, Xiaodan; Vegas Olmos, Juan José

    2013-01-01

    report on error free transmission over 20 km of standard single mode fiber and 1 m of wireless distance. Furthermore, the efficiency of photonic RF generation depending on the value of carrier suppression is reported. We argue that transport of RoF signals with low carrier suppression assisted...... with simplified techniques of lightwave generation, baseband data modulation, and RF downconversion might be a promising enabling technology for fiber support of close-proximity wireless terminals....

  3. Radiation-hard/high-speed parallel optical links

    International Nuclear Information System (INIS)

    Gan, K.K.; Buchholz, P.; Heidbrink, S.; Kagan, H.P.; Kass, R.D.; Moore, J.; Smith, D.S.; Vogt, M.; Ziolkowski, M.

    2016-01-01

    We have designed and fabricated a compact parallel optical engine for transmitting data at 5 Gb/s. The device consists of a 4-channel ASIC driving a VCSEL (Vertical Cavity Surface Emitting Laser) array in an optical package. The ASIC is designed using only core transistors in a 65 nm CMOS process to enhance the radiation-hardness. The ASIC contains an 8-bit DAC to control the bias and modulation currents of the individual channels in the VCSEL array. The performance of the optical engine up at 5 Gb/s is satisfactory.

  4. Compressive sensing in a photonic link with optical integration

    DEFF Research Database (Denmark)

    Chen, Ying; Yu, Xianbin; Chi, Hao

    2014-01-01

    In this Letter, we present a novel structure to realize photonics-assisted compressive sensing (CS) with optical integration. In the system, a spectrally sparse signal modulates a multiwavelength continuous-wave light and then is mixed with a random sequence in optical domain. The optical signal......, which is equivalent to the function of integration required in CS. A proof-of-concept experiment with four wavelengths, corresponding to a compression factor of 4, is demonstrated. More simulation results are also given to show the potential of the technique....

  5. Cascaded optical fiber link using the internet network for remote clocks comparison.

    Science.gov (United States)

    Chiodo, Nicola; Quintin, Nicolas; Stefani, Fabio; Wiotte, Fabrice; Camisard, Emilie; Chardonnet, Christian; Santarelli, Giorgio; Amy-Klein, Anne; Pottie, Paul-Eric; Lopez, Olivier

    2015-12-28

    We report a cascaded optical link of 1100 km for ultra-stable frequency distribution over an Internet fiber network. The link is composed of four spans for which the propagation noise is actively compensated. The robustness and the performance of the link are ensured by five fully automated optoelectronic stations, two of them at the link ends, and three deployed on the field and connecting the spans. This device coherently regenerates the optical signal with the heterodyne optical phase locking of a low-noise laser diode. Optical detection of the beat-note signals for the laser lock and the link noise compensation are obtained with stable and low-noise fibered optical interferometer. We show 3.5 days of continuous operation of the noise-compensated 4-span cascaded link leading to fractional frequency instability of 4x10(-16) at 1-s measurement time and 1x10(-19) at 2000 s. This cascaded link was extended to 1480-km with the same performance. This work is a significant step towards a sustainable wide area ultra-stable optical frequency distribution and comparison network at a very high level of performance.

  6. Fade statistics of M-turbulent optical links

    DEFF Research Database (Denmark)

    Jurado-Navas, Antonio; Maria Garrido-Balsells, Jose; Castillo-Vazquez, Miguel

    2017-01-01

    A new and generalized statistical model, called Malaga or simply M distribution, has been derived recently to characterize the irradiance fluctuations of an unbounded optical wavefront propagating through a turbulent medium under all irradiance fluctuation conditions. The aforementioned model ext...

  7. A Wireless Sensor Enabled by Wireless Power

    Science.gov (United States)

    Lee, Da-Sheng; Liu, Yu-Hong; Lin, Chii-Ruey

    2012-01-01

    Through harvesting energy by wireless charging and delivering data by wireless communication, this study proposes the concept of a wireless sensor enabled by wireless power (WPWS) and reports the fabrication of a prototype for functional tests. One WPWS node consists of wireless power module and sensor module with different chip-type sensors. Its main feature is the dual antenna structure. Following RFID system architecture, a power harvesting antenna was designed to gather power from a standard reader working in the 915 MHz band. Referring to the Modbus protocol, the other wireless communication antenna was integrated on a node to send sensor data in parallel. The dual antenna structure integrates both the advantages of an RFID system and a wireless sensor. Using a standard UHF RFID reader, WPWS can be enabled in a distributed area with a diameter up to 4 m. Working status is similar to that of a passive tag, except that a tag can only be queried statically, while the WPWS can send dynamic data from the sensors. The function is the same as a wireless sensor node. Different WPWSs equipped with temperature and humidity, optical and airflow velocity sensors are tested in this study. All sensors can send back detection data within 8 s. The accuracy is within 8% deviation compared with laboratory equipment. A wireless sensor network enabled by wireless power should be a totally wireless sensor network using WPWS. However, distributed WPWSs only can form a star topology, the simplest topology for constructing a sensor network. Because of shielding effects, it is difficult to apply other complex topologies. Despite this limitation, WPWS still can be used to extend sensor network applications in hazardous environments. Further research is needed to improve WPWS to realize a totally wireless sensor network. PMID:23443370

  8. A Wireless Sensor Enabled by Wireless Power

    Directory of Open Access Journals (Sweden)

    Da-Sheng Lee

    2012-11-01

    Full Text Available Through harvesting energy by wireless charging and delivering data by wireless communication, this study proposes the concept of a wireless sensor enabled by wireless power (WPWS and reports the fabrication of a prototype for functional tests. One WPWS node consists of wireless power module and sensor module with different chip-type sensors. Its main feature is the dual antenna structure. Following RFID system architecture, a power harvesting antenna was designed to gather power from a standard reader working in the 915 MHz band. Referring to the Modbus protocol, the other wireless communication antenna was integrated on a node to send sensor data in parallel. The dual antenna structure integrates both the advantages of an RFID system and a wireless sensor. Using a standard UHF RFID reader, WPWS can be enabled in a distributed area with a diameter up to 4 m. Working status is similar to that of a passive tag, except that a tag can only be queried statically, while the WPWS can send dynamic data from the sensors. The function is the same as a wireless sensor node. Different WPWSs equipped with temperature and humidity, optical and airflow velocity sensors are tested in this study. All sensors can send back detection data within 8 s. The accuracy is within 8% deviation compared with laboratory equipment. A wireless sensor network enabled by wireless power should be a totally wireless sensor network using WPWS. However, distributed WPWSs only can form a star topology, the simplest topology for constructing a sensor network. Because of shielding effects, it is difficult to apply other complex topologies. Despite this limitation, WPWS still can be used to extend sensor network applications in hazardous environments. Further research is needed to improve WPWS to realize a totally wireless sensor network.

  9. A wireless sensor enabled by wireless power.

    Science.gov (United States)

    Lee, Da-Sheng; Liu, Yu-Hong; Lin, Chii-Ruey

    2012-11-22

    Through harvesting energy by wireless charging and delivering data by wireless communication, this study proposes the concept of a wireless sensor enabled by wireless power (WPWS) and reports the fabrication of a prototype for functional tests. One WPWS node consists of wireless power module and sensor module with different chip-type sensors. Its main feature is the dual antenna structure. Following RFID system architecture, a power harvesting antenna was designed to gather power from a standard reader working in the 915 MHz band. Referring to the Modbus protocol, the other wireless communication antenna was integrated on a node to send sensor data in parallel. The dual antenna structure integrates both the advantages of an RFID system and a wireless sensor. Using a standard UHF RFID reader, WPWS can be enabled in a distributed area with a diameter up to 4 m. Working status is similar to that of a passive tag, except that a tag can only be queried statically, while the WPWS can send dynamic data from the sensors. The function is the same as a wireless sensor node. Different WPWSs equipped with temperature and humidity, optical and airflow velocity sensors are tested in this study. All sensors can send back detection data within 8 s. The accuracy is within 8% deviation compared with laboratory equipment. A wireless sensor network enabled by wireless power should be a totally wireless sensor network using WPWS. However, distributed WPWSs only can form a star topology, the simplest topology for constructing a sensor network. Because of shielding effects, it is difficult to apply other complex topologies. Despite this limitation, WPWS still can be used to extend sensor network applications in hazardous environments. Further research is needed to improve WPWS to realize a totally wireless sensor network.

  10. Eight-channel video broadcast feed service using free-space optical wireless technology at the Sydney 2000 Olympic Games

    Science.gov (United States)

    Szajowski, Paul F.; Rigas, A. J.; Robinson, J. W.; Nykolak, Gerald; Paulson, Bruce D.; Tourgee, G. E.; Auborn, James J.

    2001-02-01

    12 Terrestrial 1550 nm WDM free-space optical communication systems have been demonstrated to provide a viable means to transport data, voice and video channels for point-to-point applications without the use of optical fiber. Key features of free-space optical transmission systems are their ability to utilize present day telecommunication components such as: laser diode transmitters, high-power optical amplifiers operating within the 1550 nm optical transmission window and high-sensitivity optical receivers designed for multi-Giga- bit data rates. In this paper, we report on details of the world's first field test, demonstrating real time video transmission of eight uncompressed standard-definition (SD) video channels operating at an aggregate data rate of 1.485 Gb/s over a 0.89 km terrestrial free-space link. This data link was used in support of the 2000 Olympic games held recently in Sydney, Australia. Results from this eight- channel SD terrestrial free-space laser communications systems are presented. The transmission system operated error-free continuously from September 14, 2000 until October 1, 2000, twenty-four hours a day, throughout the coverage of the games. Modeling results predict that free- space SD video transmission systems can be designed and operated over significant link distances under nominal visibility conditions.

  11. A reliable low-cost wireless and wearable gait monitoring system based on a plastic optical fibre sensor

    International Nuclear Information System (INIS)

    Bilro, L; Pinto, J L; Oliveira, J G; Nogueira, R N

    2011-01-01

    A wearable and wireless system designed to evaluate quantitatively the human gait is presented. It allows knee sagittal motion monitoring over long distances and periods with a portable and low-cost package. It is based on the measurement of transmittance changes when a side-polished plastic optical fibre is bent. Four voluntary healthy subjects, on five different days, were tested in order to assess inter-day and inter-subject reliability. Results have shown that this technique is reliable, allows a one-time calibration and is suitable in the diagnosis and rehabilitation of knee injuries or for monitoring the performance of competitive athletes. Environmental testing was accomplished in order to study the influence of different temperatures and humidity conditions

  12. High-Capacity 60 GHz and 75–110 GHz Band Links Employing All-Optical OFDM Generation and Digital Coherent Detection

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio; Zibar, Darko; Sambaraju, Rakesh

    2012-01-01

    The performance of wireless signal generation and detection at millimeter-wave frequencies using baseband optical means is analyzed and experimentally demonstrated. Multigigabit wireless signal generation is achieved based on all-optical orthogonal frequency division multiplexing (OFDM) and photo......The performance of wireless signal generation and detection at millimeter-wave frequencies using baseband optical means is analyzed and experimentally demonstrated. Multigigabit wireless signal generation is achieved based on all-optical orthogonal frequency division multiplexing (OFDM...... scalability and bit-rate transparency of our proposed approach, we experimentally demonstrated generation and detection in the 60 GHz and 75–110 GHz band of an all-optical OFDM quadrature phase shift keying, with two and three subcarriers, for a total bit rate over 20 Gb/ s....

  13. Fiber-supported 60 GHz mobile backhaul links for access/metropolitan deployment

    DEFF Research Database (Denmark)

    Lebedev, Alexander; Pang, Xiaodan; Vegas Olmos, Juan José

    2013-01-01

    We present a 60 GHz wireless link fully supported with the optical fiber infrastructure. The architecture that we implement is suitable to provide the efficient wireless/fiber mobile backhaul in access/metropolitan area. Bit error rate (BER) performance below the 7% overhead forward error...

  14. Transport Schemes for Fiber-Wireless Technology: Transmission Performance and Energy Efficiency

    Directory of Open Access Journals (Sweden)

    Christina Lim

    2014-04-01

    Full Text Available Fiber-wireless technology has been actively researched as a potential candidate for next generation broadband wireless signal distribution. Despite the popularity, this hybrid scheme has many technical challenges that impede the uptake and commercial deployment. One of the inherent issues is the transport of the wireless signals over a predominantly digital optical network in today’s telecommunication infrastructure. Many different approaches have been introduced and demonstrated with digitized RF transport of the wireless signals being the most compatible with the existing optical fiber networks. In this paper, we review our work in the area of digitized RF transport to address the inherent issues related to analog transport in the fiber-wireless links and compare the transmission performance and energy efficiency with the other transport strategies.

  15. O-band 400 Gbit/s client side optical transmission link

    DEFF Research Database (Denmark)

    Zuo, Tianjian; Tatarczak, Anna; Iglesias Olmedo, Miguel

    2014-01-01

    We present an O-band 400 Gbit/s optical client side Ethernet link with 40 km SSMF reach employing four LAN-WDM lanes, MultiCAP modulation and direct detection.......We present an O-band 400 Gbit/s optical client side Ethernet link with 40 km SSMF reach employing four LAN-WDM lanes, MultiCAP modulation and direct detection....

  16. Potential Upgrade of the CMS Tracker Analog Readout Optical Links Using Bandwidth Efficient Digital Modulation

    OpenAIRE

    Dris, Stefanos; Foudas, Costas; Gill, Karl; Grabit, Robert; Ricci, Daniel; Troska, Jan; Vasey, Francois

    2010-01-01

    The potential application of advanced digital communication schemes in a future upgrade of the CMS Tracker readout optical links is currently being investigated at CERN. We show experimentally that multi-Gbit/s data rates are possible over the current 40 MSamples/s analog optical links by employing techniques similar to those used in ADSL. The concept involves using one or more digitally-modulated sinusoidal carriers in order to make efficient use of the available bandwidth.

  17. DSP based coherent receiver for phase-modulated radio-over-fiber optical links

    DEFF Research Database (Denmark)

    Zibar, Darko; Tafur Monroy, Idelfonso; Peucheret, Christophe

    2008-01-01

    A novel DSP based coherent receiver for phase modulated radio-over-fiber optical links is reported. Using the proposed digital receiver, signal demodulation of 1.25 Gb/s ASK-modulated 10 GHz RF carrier is experimentally demonstrated.......A novel DSP based coherent receiver for phase modulated radio-over-fiber optical links is reported. Using the proposed digital receiver, signal demodulation of 1.25 Gb/s ASK-modulated 10 GHz RF carrier is experimentally demonstrated....

  18. Potential Upgrade of the CMS Tracker Analog Readout Optical Links using Bandwidth Efficient Digital Modulation

    CERN Document Server

    Dris, Stefanos; Gill, K; Grabit, R; Ricci, D; Troska, J; Vasey, F

    2007-01-01

    The potential application of advanced digital communication schemes in a future upgrade of the CMS Tracker readout optical links is currently being investigated at CERN. We show experimentally that multi-Gbit/s data rates are possible over the current 40 MSamples/s analog optical links by employing techniques similar to those used in ADSL. The concept involves using one or more digitally-modulated sinusoidal carriers in order to make efficient use of the available bandwidth.

  19. Reconfigurable Radio Access Unit for DWDM to W-Band Wireless Conversion

    DEFF Research Database (Denmark)

    Chorchos, Łukasz; Rommel, Simon; Turkiewicz, Jarosław P.

    2017-01-01

    In this letter a reconfigurable Remote Access Unit (RAU) is proposed and demonstrated, interfacing dense wavelength division multiplexed (DWDM) optical and W-band wireless links. The RAU is composed of a tunable local oscillator, a narrow optical filter and a control unit, making it reconfigurable...

  20. Development of Innovative and Inexpensive Optical Sensors in Wireless Ad-hoc Sensor Networks for Environmental Monitoring

    Science.gov (United States)

    Mollenhauer, Hannes; Schima, Robert; Assing, Martin; Mollenhauer, Olaf; Dietrich, Peter; Bumberger, Jan

    2015-04-01

    Due to the heterogeneity and dynamic of ecosystems, the observation and monitoring of natural processes necessitate a high temporal and spatial resolution. This also requires inexpensive and adaptive measurements as well as innovative monitoring strategies. To this end, the application of ad-hoc wireless sensor networks holds the potential of creating an adequate monitoring platform. In order to achieve a comprehensive monitoring in space and time with affordability, it is necessary to reduce the sensor costs. Common investigation methods, especially with regard to vegetation processes, are based on optical measurements. In particular, different wavelengths correspond to specific properties of the plants and preserve the possibility to derive information about the ecosystem, e.g. photosynthetic performance or nutrient content. In this context, photosynthetically active radiation (PAR) sensors and hyperspectral sensors are in major use. This work aims the development, evaluation and application of inexpensive but high performance optical sensors for the implementation in wireless sensor networks. Photosynthetically active radiation designates the spectral range from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis. PAR sensors enable the detection of the reflected solar light of the vegetation in the whole PAR wave band. The amount of absorption indicates photosynthetic activity of the plant, with good approximation. Hyperspectral sensors observe specific parts or rather distinct wavelengths of the solar light spectrum and facilitate the determination of the main pigment classes, e.g. Chlorophyll, Carotenoid and Anthocyanin. Due to the specific absorption of certain pigments, a characteristic spectral signature can be seen in the visible part of the electromagnetic spectrum, known as narrow-band peaks. In an analogous manner, also the presence and concentration of different nutrients cause a characteristic spectral

  1. Mach-Zehnder Fiber-Optic Links for ICF Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Miller, E. K., Hermann, H. W.

    2012-11-01

    This article describes the operation and evolution of Mach-Zehnder links for single-point detectors in inertial confinement fusion experimental facilities, based on the Gamma Reaction History (GRH) diagnostic at the National Ignition Facility.

  2. Highly linear and transparent 3-18 GHz optical microwave link

    DEFF Research Database (Denmark)

    Nielsen, Torben Nørskov; Gliese, Ulrik Bo; Christensen, T.

    1994-01-01

    A highly linear optical microwave link transmitter based on heterodyne phase-locked DFB lasers is presented. The transmitter is transparent for FM and PM input signals with carrier frequencies ranging from 3-18 GHz. Distortion-free transmission of a 7.6 GHz FM PAL video signal over 25 km of optical...

  3. Optimal threshold detection for Málaga turbulent optical links

    DEFF Research Database (Denmark)

    Jurado-Navas, Antonio; Garrido-Balsellss, José María; del Castillo Vázquez, Miguel

    2016-01-01

    in this paper the role of the detection threshold in a free-space optical system employing an on-off keying modulation technique and involved in different scenarios, and taking into account the extinction ratio associated to the employed laser. First we have derived some analytical expressions for the lower...

  4. Characteristics of VCSELs and VCSEL arrays for optical data links

    Science.gov (United States)

    Gaw, Craig A.; Jiang, Wenbin; Lebby, Michael S.; Kiely, Philip A.; Claisse, Paul R.

    1997-05-01

    High performance, low cost, and highly reliable vertical cavity surface emitting lasers (VCSELs) have been developed and are currently being used in both parallel and serial optical interconnect applications. For example, Motorola's OPTOBUSTM parallel optical interconnect relies heavily on the unique characteristics of arrays of GaAs based VCSELs emitting at 850 nm to achieve its stringent performance goals at low cost. Representative parametric results of discrete VCSELs and VCSEL arrays will be compared, including `optical power output-current' and `current-voltage' curves, optical wall plug efficiencies, and modulation characteristics. The use of statistical parameter analysis across a wafer and subsequent parametric wafer maps has proven to be a valuable tool for maintaining control of the fabrication process. The consistency of VCSEL parameters across individual VCSEL arrays will be discussed. VCSELs are very robust devices. Life times at room ambient in excess of 3E6 hours have been reported by several groups. Degradation behavior of selected device parameters will be discussed. Failure analysis demonstrating the effect of proton implant depth on reliability will be presented. ESD damage at forward bias is shown to be process related, while ESD damage at reverse bias is shown to be material related. These VCSELs are ESD Class 1 devices.

  5. Testing Time and Frequency Fiber-Optic Link Transfer by Hardware Emulation of Acoustic-Band Optical Noise

    Directory of Open Access Journals (Sweden)

    Lipiński Marcin

    2016-06-01

    Full Text Available The low-frequency optical-signal phase noise induced by mechanical vibration of the base occurs in field-deployed fibers. Typical telecommunication data transfer is insensitive to this type of noise but the phenomenon may influence links dedicated to precise Time and Frequency (T&F fiber-optic transfer that exploit the idea of stabilization of phase or propagation delay of the link. To measure effectiveness of suppression of acoustic noise in such a link, a dedicated measurement setup is necessary. The setup should enable to introduce a low-frequency phase corruption to the optical signal in a controllable way. In the paper, a concept of a setup in which the mechanically induced acoustic-band optical signal phase corruption is described and its own features and measured parameters are presented. Next, the experimental measurement results of the T&F transfer TFTS-2 system’s immunity as a function of the fibre-optic length vs. the acoustic-band noise are presented. Then, the dependency of the system immunity on the location of a noise source along the link is also pointed out.

  6. High-Capacity Short-Range Optical Communication Links

    DEFF Research Database (Denmark)

    Tatarczak, Anna

    offered by data centers. As the popularity of cloud computing soars, the demand for high-speed, short-range data center links grows. Vertical cavity surface emitting lasers (VCSEL) and multimode fibers (MMF) prove especially well-suited for such scenarios. VCSELs have high modulation bandwidths......, are energy efficient, reliable, and cheap to fabricate. MMFs are highly tolerant to coupling misalignment and bending. However, because of the large spectral width of VCSELs and, consequently, chromatic and modal dispersion effects in the fiber, the VCSEL-MMF links have a limited bandwidth{distance product...

  7. High capacity wireless data links in the W-band using hybrid photonics-electronic techniques for signal generation and detection

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

    2014-01-01

    , is seeding the need to use bands located at the millimeter-wave region (30–300 GHz), mainly because of its inherent broadband nature. In our lab, we have conducted extensive research on high-speed photonic-wireless links in the V-band (50–75GHz) and the W-band (75–110GHz). In this paper, we will present our...... latest findings and experimental results on the W-band, specifically on its 81–86GHz sub-band. These include photonic generation of millimeter-wave carriers and transmission performance of broadband signals on different types of fibers and span lengths....

  8. HDTV codec for high rate transmission on fiber optic links

    Science.gov (United States)

    Antkowiak, Jochen

    1993-11-01

    The transmission of HDTV picture signals is usually carried out by bit rate reduced coding. The compression factor must be kept low for contribution quality. An HDTV codec based on DPCM processing was built to feed high performance video links including the transmission of audio channels. The data rate at the codec output is 648 Mbit/s.

  9. A wireless implantable switched-capacitor based optogenetic stimulating system.

    Science.gov (United States)

    Lee, Hyung-Min; Kwon, Ki-Yong; Li, Wen; Ghovanloo, Maysam

    2014-01-01

    This paper presents a power-efficient implantable optogenetic interface using a wireless switched-capacitor based stimulating (SCS) system. The SCS efficiently charges storage capacitors directly from an inductive link and periodically discharges them into an array of micro-LEDs, providing high instantaneous power without affecting wireless link and system supply voltage. A custom-designed computer interface in LabVIEW environment wirelessly controls stimulation parameters through the inductive link, and an optrode array enables simultaneous neural recording along with optical stimulation. The 4-channel SCS system prototype has been implemented in a 0.35-μm CMOS process and combined with the optrode array. In vivo experiments involving light-induced local field potentials verified the efficacy of the SCS system. An implantable version of the SCS system with flexible hermetic sealing is under development for chronic experiments.

  10. A Wireless Implantable Switched-Capacitor Based Optogenetic Stimulating System

    Science.gov (United States)

    Lee, Hyung-Min; Kwon, Ki-Yong; Li, Wen

    2015-01-01

    This paper presents a power-efficient implantable optogenetic interface using a wireless switched-capacitor based stimulating (SCS) system. The SCS efficiently charges storage capacitors directly from an inductive link and periodically discharges them into an array of micro-LEDs, providing high instantaneous power without affecting wireless link and system supply voltage. A custom-designed computer interface in LabVIEW environment wirelessly controls stimulation parameters through the inductive link, and an optrode array enables simultaneous neural recording along with optical stimulation. The 4-channel SCS system prototype has been implemented in a 0.35-μm CMOS process and combined with the optrode array. In vivo experiments involving light-induced local field potentials verified the efficacy of the SCS system. An implantable version of the SCS system with flexible hermetic sealing is under development for chronic experiments. PMID:25570099

  11. The Young-Laplace equation links capillarity with geometrical optics

    CERN Document Server

    Rodriguez-Valverde, M A; Hidalgo-Alvarez, R

    2003-01-01

    Analogies in physics are unusual coincidences that can be very useful to solve problems and to clarify some theoretical concepts. Apart from their own curiosity, analogies are attractive tools because they reduce the abstraction of some complex phenomena in such a way that these can be understood by means of other phenomena closer to daily experience. Usually, two analogous systems share a common aspect, like the movement of particles or transport of matter. On account of this, the analogy presented is exceptional since the involved phenomena are a priori disjoined. The most important equation of capillarity, the Young-Laplace equation, has the same structure as the Gullstrand equation of geometrical optics, which relates the optic power of a thick lens to its geometry and the properties of the media.

  12. Spectrally and Energy Efficient OFDM (SEE-OFDM) for Intensity Modulated Optical Wireless Systems

    OpenAIRE

    Lam, Emily; Wilson, Sarah Kate; Elgala, Hany; Little, Thomas D. C.

    2015-01-01

    Spectrally and energy efficient orthogonal frequency division multiplexing (SEE-OFDM) is an optical OFDM technique based on combining multiple asymmetrically clipped optical OFDM (ACO-OFDM) signals into one OFDM signal. By summing different components together, SEE-OFDM can achieve the same spectral efficiency as DC-biased optical OFDM (DCO-OFDM) without an energy-inefficient DC-bias. This paper introduces multiple methods for decoding a SEE-OFDM symbol and shows that an iterative decoder wit...

  13. Phase-coherent frequency comparison of optical clocks using a telecommunication fiber link.

    Science.gov (United States)

    Schnatz, Harald; Terra, Osama; Predehl, Katharina; Feldmann, Thorsten; Legero, Thomas; Lipphardt, Burghard; Sterr, Uwe; Grosche, Gesine; Holzwarth, Ronald; Hänsch, Theodor W; Udem, Thomas; Lu, Zehuang H; Wang, Li J; Ertmer, Wolfgang; Friebe, Jan; Pape, Andrè; Rasel, Ernst-M; Riedmann, Mathias; Wübbena, Temmo

    2010-01-01

    We have explored the performance of 2 "dark fibers" of a commercial telecommunication fiber link for a remote comparison of optical clocks. These fibers establish a network in Germany that will eventually link optical frequency standards at PTB with those at the Institute of Quantum Optics (IQ) at the Leibniz University of Hanover, and the Max Planck Institutes in Erlangen (MPL) and Garching (MPQ). We demonstrate for the first time that within several minutes a phase coherent comparison of clock lasers at the few 10(-15) level can also be accomplished when the lasers are more than 100 km apart. Based on the performance of the fiber link to the IQ, we estimate the expected stability for the link from PTB to MPQ via MPL that bridges a distance of approximately 900 km.

  14. High-speed underwater optical wireless communication using a blue GaN-based micro-LED.

    Science.gov (United States)

    Tian, Pengfei; Liu, Xiaoyan; Yi, Suyu; Huang, Yuxin; Zhang, Shuailong; Zhou, Xiaolin; Hu, Laigui; Zheng, Lirong; Liu, Ran

    2017-01-23

    High-speed underwater optical wireless communication (UOWC) was achieved using an 80 μm blue-emitting GaN-based micro-LED. The micro-LED has a peak emission wavelength of ~440 nm and an underwater power attenuation of 1 dB/m in tap water. The -3 dB electrical-to-optical modulation bandwidth of the packaged micro-LED increases with increasing current and saturates at ~160 MHz. At an underwater distance of 0.6 m, 800 Mb/s data rate was achieved with a bit error rate (BER) of 1.3 × 10-3, below the forward error correction (FEC) criteria. And we obtained 100 Mb/s data communication speed with a received light output power of -40 dBm and a BER of 1.9 × 10-3, suggesting that UOWC with extended distance can be achieved. Through reflecting the light emission beam by mirrors within a water tank, we experimentally demonstrated a 200 Mb/s data rate with a BER of 3.0 × 10-6 at an underwater distance of 5.4 m.

  15. On the Optimality of Repetition Coding among Rate-1 DC-offset STBCs for MIMO Optical Wireless Communications

    KAUST Repository

    Sapenov, Yerzhan

    2017-07-06

    In this paper, an optical wireless multiple-input multiple-output communication system employing intensity-modulation direct-detection is considered. The performance of direct current offset space-time block codes (DC-STBC) is studied in terms of pairwise error probability (PEP). It is shown that among the class of DC-STBCs, the worst case PEP corresponding to the minimum distance between two codewords is minimized by repetition coding (RC), under both electrical and optical individual power constraints. It follows that among all DC-STBCs, RC is optimal in terms of worst-case PEP for static channels and also for varying channels under any turbulence statistics. This result agrees with previously published numerical results showing the superiority of RC in such systems. It also agrees with previously published analytic results on this topic under log-normal turbulence and further extends it to arbitrary turbulence statistics. This shows the redundancy of the time-dimension of the DC-STBC in this system. This result is further extended to sum power constraints with static and turbulent channels, where it is also shown that the time dimension is redundant, and the optimal DC-STBC has a spatial beamforming structure. Numerical results are provided to demonstrate the difference in performance for systems with different numbers of receiving apertures and different throughput.

  16. Optically envelope detected QAM and QPSK RF modulated signals in hybrid wireless-fiber systems

    DEFF Research Database (Denmark)

    Tafur Monroy, Idelfonso; Prince, Kamau; Seoane, Jorge

    2009-01-01

    We experimentally demonstrate optical envelope detection of 40 Mbaud 16-QAM and QPSK RF modulated signals. The proposed system employs an electro-absorption modulator performing the function of an optical halfwave rectifier. In this experiment, the QAM and QPSK signals are frequency down converted...

  17. Optical sensing system based on wireless paired emitter detector diode device and ionogels for lab-on-a-disc water quality analysis.

    Science.gov (United States)

    Czugala, Monika; Gorkin, Robert; Phelan, Thomas; Gaughran, Jennifer; Curto, Vincenzo Fabio; Ducrée, Jens; Diamond, Dermot; Benito-Lopez, Fernando

    2012-12-07

    This work describes the first use of a wireless paired emitter detector diode device (PEDD) as an optical sensor for water quality monitoring in a lab-on-a-disc device. The microfluidic platform, based on an ionogel sensing area combined with a low-cost optical sensor, is applied for quantitative pH and qualitative turbidity monitoring of water samples at point-of-need. The autonomous capabilities of the PEDD system, combined with the portability and wireless communication of the full device, provide the flexibility needed for on-site water testing. Water samples from local fresh and brackish sources were successfully analysed using the device, showing very good correlation with standard bench-top systems.

  18. 26 m/5.5 Gbps air-water optical wireless communication based on an OFDM-modulated 520-nm laser diode.

    Science.gov (United States)

    Chen, Yifei; Kong, Meiwei; Ali, Tariq; Wang, Jiongliang; Sarwar, Rohail; Han, Jun; Guo, Chaoyang; Sun, Bing; Deng, Ning; Xu, Jing

    2017-06-26

    We experimentally demonstrate a high-speed air-water optical wireless communication system with both downlink and uplink transmission employing 32-quadrature amplitude modulation (QAM) orthogonal frequency division multiplexing (OFDM) and a single-mode pigtailed green-light laser diode (LD). This work is an important step towards the future study on optical wireless communications between underwater platforms and airborne terminals. Over a 5-m air channel and a 21-m water channel, we achieve a 5.3-Gbps transmission without power loading (PL) and a 5.5-Gbps transmission with PL in the downlink. The corresponding bit error rates (BERs) are 2.64×10 -3 and 2.47×10 -3 , respectively, which are below the forward error correction (FEC) criterion. A data rate of 5.5 Gbps with PL at a BER of 2.92×10 -3 is also achieved in the uplink.

  19. Optical fiber link for transmission of 1-nJ femtosecond laser pulses at 1550 nm

    DEFF Research Database (Denmark)

    Eichhorn, Finn; Olsson, Rasmus Kjelsmark; Buron, Jonas Christian Due

    2010-01-01

    a distance of 5.3 m. The fiber link consists of dispersion-compensating fiber (DCF) and standard single-mode fiber. The optical pulses at different positions in the fiber link are measured using frequency-resolved optical gating (FROG). The results are compared with numerical simulations of the pulse......We report on numerical and experimental characterization of the performance of a fiber link optimized for the delivery of sub-100-fs laser pulses at 1550 nm over several meters of fiber. We investigate the power handling capacity of the link, and demonstrate all-fiber delivery of 1-nJ pulses over...... propagation based on the generalized nonlinear Schrödinger equation. The high input power capacity of the fiber link allows the splitting and distribution of femtosecond pulses to an array of fibers with applications in multi-channel fiber-coupled terahertz time-domain spectroscopy and imaging systems. We...

  20. Multi-link faults localization and restoration based on fuzzy fault set for dynamic optical networks.

    Science.gov (United States)

    Zhao, Yongli; Li, Xin; Li, Huadong; Wang, Xinbo; Zhang, Jie; Huang, Shanguo

    2013-01-28

    Based on a distributed method of bit-error-rate (BER) monitoring, a novel multi-link faults restoration algorithm is proposed for dynamic optical networks. The concept of fuzzy fault set (FFS) is first introduced for multi-link faults localization, which includes all possible optical equipment or fiber links with a membership describing the possibility of faults. Such a set is characterized by a membership function which assigns each object a grade of membership ranging from zero to one. OSPF protocol extension is designed for the BER information flooding in the network. The BER information can be correlated to link faults through FFS. Based on the BER information and FFS, multi-link faults localization mechanism and restoration algorithm are implemented and experimentally demonstrated on a GMPLS enabled optical network testbed with 40 wavelengths in each fiber link. Experimental results show that the novel localization mechanism has better performance compared with the extended limited perimeter vector matching (LVM) protocol and the restoration algorithm can improve the restoration success rate under multi-link faults scenario.

  1. On the performance of free-space optical wireless communication systems over double generalized gamma fading channels

    KAUST Repository

    Al-Quwaiee, Hessa

    2014-03-01

    Starting with the double generalized Gamma (GG) model that was proposed in [1] to describe turbulence-induced fading in free-space optical (FSO) systems, we propose a new unified model which accounts for the impact of pointing errors and type of receiver detector. Based on this new unified model, we study the performance of FSO links operating over these kind of channels. All our analytical results are verified using computer based Monte-Carlo simulations. © 2014 IEEE.

  2. Performance emulation and parameter estimation for nonlinear fibre-optic links

    DEFF Research Database (Denmark)

    Piels, Molly; Porto da Silva, Edson; Zibar, Darko

    2016-01-01

    Fibre-optic communication systems, especially when operating in the nonlinear regime, generally do not perform exactly as theory would predict. A number of methods for data-based evaluation of nonlinear fibre-optic link parameters, both for accurate performance emulation and optimization, are rev......Fibre-optic communication systems, especially when operating in the nonlinear regime, generally do not perform exactly as theory would predict. A number of methods for data-based evaluation of nonlinear fibre-optic link parameters, both for accurate performance emulation and optimization......, are reviewed. In particular, single-step nonlinear impairment based on the Gaussian mixture model, adaptive digital backpropagation, and extension to higher-dimensional spaces using Monte Carlo Markov chains are discussed....

  3. Gigabit optical link test system for RPC muon trigger in the CMS experiment

    CERN Document Server

    Pozniak, Krzysztof T; Kierzkowski, K; Kudla, I M; Pietrusinski, M; Ptak, M; Romaniuk, Ryszard; Ungaro, D; Wrochna, G

    2002-01-01

    High-energy experiments like Atlas, Alice, CMS or LHCb at the LHC accelerator at CERN will be performed in very harsh conditions for electronic equipment. High radiation level in the experimental halls causes that commonly available electronic devices do not work properly. A specialized optical transmitter - GOL (gigabit optical link) has been designed at CERN to meet the radiation environment requirements. The design goal was to supply device resistant to high radiation, fast, and being able to transmit data through optical links. Transmitter was designed considering two important characteristics of its work environment: high radiation level and gigabit transmission speed. Proper internal structure of GOL chip allows to minimize single event upsets (SEU) caused by ionizing radiation. Unfortunately, the design does not eliminate SEU completely. This paper presents testing system for the GOL. Its main purpose is testing new prototypes of optical fibre gigabit transmission systems using GOL transmitter and comm...

  4. A Study of an Optical Lunar Surface Communications Network with High Bandwidth Direct to Earth Link

    Science.gov (United States)

    Wilson, K.; Biswas, A.; Schoolcraft, J.

    2011-01-01

    Analyzed optical DTE (direct to earth) and lunar relay satellite link analyses, greater than 200 Mbps downlink to 1-m Earth receiver and greater than 1 Mbps uplink achieved with mobile 5-cm lunar transceiver, greater than 1Gbps downlink and greater than 10 Mpbs uplink achieved with 10-cm stationary lunar transceiver, MITLL (MIT Lincoln Laboratory) 2013 LLCD (Lunar Laser Communications Demonstration) plans to demonstrate 622 Mbps downlink with 20 Mbps uplink between lunar orbiter and ground station; Identified top five technology challenges to deploying lunar optical network, Performed preliminary experiments on two of challenges: (i) lunar dust removal and (ii)DTN over optical carrier, Exploring opportunities to evaluate DTN (delay-tolerant networking) over optical link in a multi-node network e.g. Desert RATS.

  5. Radiation-hard/high-speed parallel optical links

    Science.gov (United States)

    Gan, K. K.; Buchholz, P.; Kagan, H. P.; Kass, R. D.; Moore, J.; Smith, D. S.; Wiese, A.; Ziolkowski, M.

    2014-11-01

    We have designed an ASIC for use in a parallel optical engine for a new layer of the ATLAS pixel detector in the initial phase of the LHC luminosity upgrade. The ASIC is a 12-channel VCSEL (Vertical Cavity Surface Emitting Laser) array driver capable of operating up to 5 Gb/s per channel. The ASIC is designed using a 130 nm CMOS process to enhance the radiation-hardness. A scheme for redundancy has also been implemented to allow bypassing of a broken VCSEL. The ASIC also contains a power-on reset circuit that sets the ASIC to a default configuration with no signal steering. In addition, the bias and modulation currents of the individual channels are programmable. The performance of the first prototype ASIC up to 5 Gb/s is satisfactory. Furthermore, we are able to program the bias and modulation currents and to bypass a broken VCSEL channel. We are currently upgrading our design to allow operation at 10 Gb/s per channel yielding an aggregated bandwidth of 120 Gb/s. Some preliminary results of the design will be presented.

  6. Radiation-hard/high-speed parallel optical links

    International Nuclear Information System (INIS)

    Gan, K.K.; Buchholz, P.; Kagan, H.P.; Kass, R.D.; Moore, J.; Smith, D.S.; Wiese, A.; Ziolkowski, M.

    2014-01-01

    We have designed an ASIC for use in a parallel optical engine for a new layer of the ATLAS pixel detector in the initial phase of the LHC luminosity upgrade. The ASIC is a 12-channel VCSEL (Vertical Cavity Surface Emitting Laser) array driver capable of operating up to 5 Gb/s per channel. The ASIC is designed using a 130 nm CMOS process to enhance the radiation-hardness. A scheme for redundancy has also been implemented to allow bypassing of a broken VCSEL. The ASIC also contains a power-on reset circuit that sets the ASIC to a default configuration with no signal steering. In addition, the bias and modulation currents of the individual channels are programmable. The performance of the first prototype ASIC up to 5 Gb/s is satisfactory. Furthermore, we are able to program the bias and modulation currents and to bypass a broken VCSEL channel. We are currently upgrading our design to allow operation at 10 Gb/s per channel yielding an aggregated bandwidth of 120 Gb/s. Some preliminary results of the design will be presented

  7. Design and implementation of a fiber optic link for a token ring local area network

    OpenAIRE

    Doran, Thomas J.

    1992-01-01

    Approved for public release; distribution is unlimited This thesis described the design and implementation of a fiber optic link for a token ring local area network (LAN). It features the use of fiber optic channels as the transmission medium between a computer system and a wiring concentrator to convert a physical ring design into a star-wired configuration. The LAN was controlled by the TMS380 LAN Adapter chipset, which provided all diagnostic and network management features to include...

  8. Audio frequency pulse code modulation data link using an optical fiber

    Science.gov (United States)

    Blackburn, J. A.

    1981-02-01

    A simple, economical and inherently noise-immune asynchronous digital data link design that uses pulse code modulation and a fiber-optic cable is presented. Suitable for audio and instrumentation applications with typical bandwidths of dc-10 kHz, the system samples input signals at 20 kHz and converts them to a seven-bit binary code for transmission through a 20-foot length step index fiber-optic cable. Performance tests of the system, installed in a high fidelity stereo to link a casette recorder output to an amplifier's AUX input, demonstrated dramatic reductions of the hiss associated with quantization noise.

  9. Optical power transfer and communication methods for wireless implantable sensing platforms.

    Science.gov (United States)

    Mujeeb-U-Rahman, Muhammad; Adalian, Dvin; Chang, Chieh-Feng; Scherer, Axel

    2015-09-01

    Ultrasmall scale implants have recently attracted focus as valuable tools for monitoring both acute and chronic diseases. Semiconductor optical technologies are the key to miniaturizing these devices to the long-sought sub-mm scale, which will enable long-term use of these devices for medical applications. This can also enable the use of multiple implantable devices concurrently to form a true body area network of sensors. We demonstrate optical power transfer techniques and methods to effectively harness this power for implantable devices. Furthermore, we also present methods for optical data transfer from such implants. Simultaneous use of these technologies can result in miniaturized sensing platforms that can allow for large-scale use of such systems in real world applications.

  10. Directly modulated green-light diode-pumped solid-state laser for underwater wireless optical communication.

    Science.gov (United States)

    Xu, Jing; Kong, Meiwei; Lin, Aobo; Song, Yuhang; Han, Jun; Xu, Zhiwei; Wu, Bo; Gao, Shiming; Deng, Ning

    2017-05-01

    It is widely known that a diode-pumped solid-state laser (DPSSL) has very limited modulation bandwidth. Recently, we directed our attention toward the opportunities for directly modulating a DPSSL to generate high-speed green-light signals, with high power and superior beam quality, which are highly desirable in underwater wireless optical communication. The constraint imposed by the limited modulation bandwidth of a DPSSL is circumvented with the strategy of orthogonal frequency-division multiplexing and power loading. With a compact DPSSL dismantled from a low-cost laser pointer, we achieve net bit rates of 108.55 Mb/s for the 64 quadrature amplitude modulation (QAM) signal at a bit error rate (BER) of 6.42×10-4 and 89.55 Mb/s for the 32 QAM signal at a BER of 4.81×10-4, respectively, over a 2 m underwater channel. When the underwater transmission distance is increased to 6 m, the BERs are still below the forward error correction (FEC) limit of 3.8×10-3.

  11. Advanced signaling technologies for high-speed digital fiber-optic links.

    Science.gov (United States)

    Stark, Andrew J; Isautier, Pierre; Pan, Jie; Pavan, Sriharsha Kota; Filer, Mark; Tibuleac, Sorin; Lingle, Robert; de Salvo, Richard; Ralph, Stephen E

    2014-09-01

    We summarize the most recent research of the Georgia Tech Terabit Optical Networking Consortium and the state-of-the-art in fiber telecommunications. These results comprise high-capacity single-mode fiber systems with digital coherent receivers and shorter-reach multimode fiber links with vertical cavity surface emitting lasers. We strongly emphasize the capabilities that sophisticated digital signal processing and electronics add to these fiber-based data transport links.

  12. Dynamic optical fiber delivery of Ka-band packet transmissions for wireless access networks

    DEFF Research Database (Denmark)

    Rodríguez Páez, Juan Sebastián; Madsen, Peter; Tafur Monroy, Idelfonso

    2017-01-01

    A Reconfigurable Radio Access Unit is presented and experimentally demonstrated. In the unit, an optical switching system is set to dynamically deliver different packets to different points in the network. The packets are transmitted wirelesslty on the Ka-band (26–40 GHz), achieving BER values...

  13. Survey of energy efficient tracking and localization techniques in buildings using optical and wireless communication media

    NARCIS (Netherlands)

    Bruintjes, Tom M.; Kokkeler, Andre B.J.; Karagiannis, Georgios; Smit, Gerard J. M.; Bellalta, Boris; Vinel, Alexey; Jonsson, Magnus; Barcelo, Jaume; Maslennikov, Roman; Chatzimisios, Periklis; Malone, David

    2012-01-01

    This paper presents a survey of beamforming, beamsteering and mobile tracking techniques. The survey was made in the context of the SOWICI project. The aim of this project is to reduce power consumption of data exchanging devices within houses. An optical fiber network is used for data transport to

  14. Estimation of optical attenuation in reduced visibility conditions in different environments across free space optics link

    Czech Academy of Sciences Publication Activity Database

    Dev, K.; Nebuloni, R.; Capsoni, C.; Fišer, Ondřej; Brázda, V.

    2017-01-01

    Roč. 11, č. 12 (2017), s. 1708-1713 ISSN 1751-8725 Institutional support: RVO:68378289 Keywords : light attenuation * optical sensors * free-space optical communication Subject RIV: DG - Athmosphere Sciences, Meteorology OBOR OECD: Meteorology and atmospheric sciences Impact factor: 1.187, year: 2016 http://digital-library.theiet.org/content/journals/10.1049/iet-map.2016.0872

  15. High Capacity Radio over Fiber Transmission Links

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio

    , it was the highest bitrate reported of a wireless signal, with complex modulation format, detected using photonic means. I have developed an analytical model to support the experimental results and performed a linearity characterization to establish engineering design rules for this type of links. The results...... confirmed that this configuration provides high linear end-to-end transmission links and is capable of transparent transport of high spectral efficient modulation formats. Furthermore, this thesis introduces a novel approach for the generation and detection of high speed wireless signals in mm......This thesis expands the state-of-the-art on the detection of high speed wireless signals using optics. Signal detection at speeds over 1 Gbps at carrier Radio Frequency (RF) ranging from 5 GHz to 100 GHz have been achieved by applying novel concepts on optical digital coherent receivers...

  16. The design of an optical link for the ATLAS Liquid Argon Calorimeter upgrade

    CERN Document Server

    Liu, T; The ATLAS collaboration

    2012-01-01

    We present the design of an optical link for the ATLAS liquid argon calorimeter upgrade. Challenging requirements are high data bandwidth (over 150 Gb/s raw data rate per board), radiation tolerance, low power consumption, high reliability, and low transmission latency. We discuss the link system design and component developments, especially those for the transmitting side that has to operate in the radiation environment. This presentation also serves as a summary of a few other presentations that detail in a particular function block of this link.

  17. Realization of OSW/AWG-based bipolar wavelength time optical CDMA for wired wireless transmissions

    Science.gov (United States)

    Yen, Chih-Ta; Huang, Jen-Fa

    2009-01-01

    This study proposes a novel radio-over-fiber (RoF) system using two-dimensional (2-D) optical code-division multiple-access (OCDMA) scheme using pseudorandom (PN) codes for the time-spreading and wavelength-hopping ( t-spreading/ λ-hopping) codes. The 2-D system is implemented using optical switches (OSWs) and arrayed-waveguide grating (AWG) routers. By constructing 2-D codes using bipolar PN codes rather than unipolar codes provides a significant increase in the maximum permissible number of active radio base stations (RBSs). In general, the phase-induced intensity noise (PIIN) generated at high optical intensities significantly degrades the performance of a conventional multi-wavelength scheme. However, the OSW-based time-spreading method employed in the current 2-D OCDMA scheme effectively suppresses the PIIN effect. Additionally, multiple-access interference (MAI) is suppressed by the use of a wavelength/time balanced detector structure in the network receivers. The numerical evaluation results demonstrate that under PIIN- and MAI-limited conditions, the proposed system outperforms a conventional multi-wavelength OCDMA scheme by using the spectral spreading scheme to suppress beating noise. Especially, the t-spreading encoder/decoder (codec) groups share the same wavelength codec and the overall complexity is reduced and system network becomes more compact.

  18. A simple optical fibre-linked remote control system for multiple devices

    Indian Academy of Sciences (India)

    MS received 11 June 2003. Abstract. We report on the development of a simple control system which can handle multiple devices through an optical fibre data link. The devices are controlled using a set of DACs through serial data communication via a serial port of a PC. Serial data from the PC get converted to parallel ...

  19. Synchronization of optical links using the GOL with the TLK2501 or StratixGX buffers

    CERN Document Server

    Aslanides, Elie; Cogan, J; Dinkespiler, B; Duval, P Y; Le Gac, R; Leroy, O; Liotard, P L; Menouni, M; Tocco, L; Tsaregorodtsev, A Yu

    2004-01-01

    In this note we clarify the synchronization design for optical links when using the GOL on the emission side, the TLK2501 deserializer from Texas Instrument or a StratixGX FPGA on the reception side. We conclude with few requirements.

  20. Multifunctional fiber-optic microwave links based on remote heterodyne detection

    DEFF Research Database (Denmark)

    Gliese, Ulrik Bo; Nielsen, Torben Nørskov; Nielsen, Søren Nørskov

    1998-01-01

    The multifunctionality of microwave links based on remote heterodyne detection (RHD) of signals from a dual-frequency laser transmitter is discussed and experimentally demonstrated in this paper. Typically, direct detection (DD) in conjunction with optical intensity modulation is used to implement...

  1. A simple optical fibre-linked remote control system for multiple devices

    Indian Academy of Sciences (India)

    We report on the development of a simple control system which can handle multiple devices through an optical fibre data link. The devices are controlled using a set of DACs through serial data communication via a serial port of a PC. Serial data from the PC get converted to parallel mode using a homemade “serial in ...

  2. A novel modulation scheme for noise reduction in analog fiber optic links

    NARCIS (Netherlands)

    Marpaung, D.A.I.; Roeloffzen, C.G.H.; van Etten, Wim; Megret, P.; Wuilpart, M.; Bette, S.; Staquet, N.

    2005-01-01

    A novel balanced modulation and detection scheme for analog fiber optic links is proposed to overcome the limitations in signal-to-noise ratio (SNR) and dynamic range (DR).In this scheme, the modulating signal is split into positive and negative halves and applied to a pair of laser diodes. Both

  3. Noise caused by semiconductor lasers in high-speed fiber-optic links

    DEFF Research Database (Denmark)

    Olsen, C. M.; Stubkjær, Kristian; Olesen, H.

    1989-01-01

    Theoretical and experimental results are presented for the signal-to-noise (S/N) ratio caused by mode partition noise, intensity noise, and reflection-induced noise in optical data links. Under given conditions an additional noise source with a S /N ratio of 20 dB will cause a power penalty of 1 d...

  4. Gigabit optical link test system for RPC muon trigger in the CMS experiment

    Science.gov (United States)

    Pozniak, Krzysztof T.; Ptak, Mariusz; Romaniuk, Ryszard S.; Kierzkowski, Krzysztof; Kudla, Ignacy M.; Pietrusinski, Michal; Wrochna, Grzegorz; Banzuzi, Kukka; Ungaro, Donatella

    2003-10-01

    High-energy experiments like Atlas, Alice, CMS or LHCb at the LHC accelerator at CERN will be performed in very harsh conditions for electronic equipment. High radiation level in the experimental halls causes that commonly available electronic devices do not work properly. A specialized optical transmitter--GOL (Gigabit Optical Link) has been designed at CERN to meet the radiation environment requirements. The design goal was to supply device resistant to high radiation, fast, and being able to transmit data through optical links. Transmitter was designed considering two important characteristics of its work environment: high radiation level and gigabit transmission speed. Proper internal structure of GOL chip allows to minimize single event upsets (SEU) caused by ionizing radiation. Unfortunately, the design does not elimiate SEU completely. This paper presents testing system for the GOL. Its main purpose is testing new prototypes of optical fiber gigabit transmission systems using GOL transmitter and commercial receiver components. The system will be implemented in the CMS experiment for control purposes. It will monitor optical link and transmission quality in the RPC detector. System consits of hardware layer and software layer. Hardware layer, based on Latera FPGA programmable devices. Software has been developed using C++ environment integrated with VME controller hardware.

  5. Link Power Budget and Traffict QoS Performance Analysis of Gygabit Passive Optical Network

    Science.gov (United States)

    Ubaidillah, A.; Alfita, R.; Toyyibah

    2018-01-01

    Data service of telecommunication network is needed widely in the world; therefore extra wide bandwidth must be provided. For this case, PT. Telekomunikasi Tbk. applies GPON (Gigabit Passive Optical Network) as optical fibre based on telecommunication network system. GPON is a point to a multipoint technology of FTTx (Fiber to The x) that transmits information signals to the subscriber over optical fibre. In GPON trunking system, from OLT (Optical Line Terminal), the network is split to many ONT (Optical Network Terminal) of the subscribers, so it causes path loss and attenuation. In this research, the GPON performance is measured from the link power budget system and the Quality of Service (QoS) of the traffic. And the observation result shows that the link power budget system of this GPON is in good condition. The link power budget values from the mathematical calculation and direct measurement are satisfy the ITU-T G984 Class B standard, that the power level must be between -8 dBm to -27 dBm. While from the traffic performance, the observation result shows that the network resource utility of the subscribers of the observed area is not optimum. The mean of subscriber utility rate is 27.985 bps for upstream and 79.687 bps for downstream. While maximally, It should be 60.800 bps for upstream and 486.400 bps for downstream.

  6. LEO-to-ground optical communications link using adaptive optics correction on the OPALS downlink

    Science.gov (United States)

    Wright, Malcolm W.; Kovalik, Joseph; Morris, Jeff; Abrahamson, Matthew; Biswas, Abhijit

    2016-03-01

    The Optical PAyload for Lasercomm Science (OPALS) experiment on the International Space Station (ISS) recently demonstrated successful optical downlinks to the NASA/JPL 1-m aperture telescope at the Optical Communication Telescope Laboratory (OCTL) located near Wrightwood, CA. A large area (200 μm diameter) free space coupled avalanche photodiode (APD) detector was used to receive video and a bit patterns at 50 Mb/s. We report on a recent experiment that used an adaptive optics system at OCTL to correct for atmospherically-induced refractive index fluctuations so that the downlink from the ISS could be coupled into a single mode fiber receiver. Stable fiber coupled power was achieved over an entire pass using a self-referencing interferometer based adaptive optics system that was provided and operated by Boeing Co. and integrated to OCTL. End-to-end transmission and reconstruction of an HD video signal verified the communication performance as in the original OPALS demonstration. Coupling the signal into a single mode fiber opens the possibility for higher bandwidth and efficiency modulation schemes and serves as a pilot experiment for future implementations.

  7. Comparative analysis of algorithms for compensation of nonlinear distortions in fibre-optic links

    Science.gov (United States)

    Burdin, V. A.; Bourdine, A. V.; Grigorov, I. V.

    2017-12-01

    We report the results of numerical modelling and comparative analysis of two algorithms for digital signal processing intended for signal demodulation in fibre-optic links (FOLs) operating in a nonlinear mode. The first algorithm is based on the use of nonlinear Schrödinger filters and the second one utilises the ‘reception in general with bit-by-bit decision making’ technique. It is found that the latter algorithm is more noiseproof, compared to the first one (with a SNR gain of about 0.5 dB), in single-channel fibre-optic links, and its operation does not require knowledge of the link parameters; therefore, the second algorithm can also be constructed for wavelength-division multiplexing systems.

  8. Atmospheric-Fade-Tolerant Tracking and Pointing in Wireless Optical Communication

    Science.gov (United States)

    Ortiz, Gerardo; Lee, Shinhak

    2003-01-01

    An acquisition, tracking, and pointing (ATP) system, under development at the time of reporting the information for this article, is intended to enable a terminal in a free-space optical communication system to continue to aim its transmitting laser beam toward a receiver at a remote terminal when the laser beacon signal from the remote terminal temporarily fades or drops out of sight altogether. Such fades and dropouts can be caused by adverse atmospheric conditions (e.g., rain or clouds). They can also occur when intervening objects block the line of sight between terminals as a result of motions of those objects or of either or both terminals

  9. Augmenting the spectral efficiency of enhanced PAM-DMT-based optical wireless communications.

    Science.gov (United States)

    Islim, Mohamed Sufyan; Haas, Harald

    2016-05-30

    The energy efficiency of pulse-amplitude-modulated discrete multitone modulation (PAM-DMT) decreases as the modulation order of M-PAM modulation increases. Enhanced PAM-DMT (ePAM-DMT) was proposed as a solution to the reduced energy efficiency of PAM-DMT. This was achieved by allowing multiple streams of PAM-DMT to be superimposed and successively demodulated at the receiver side. In order to maintain a distortion-free unipolar ePAM-DMT system, the multiple time-domain PAM-DMT streams are required to be aligned. However, aligning the antisymmetry in ePAM-DMT is complex and results in efficiency losses. In this paper, a novel simplified method to apply the superposition modulation on M-PAM modulated discrete multitone (DMT) is introduced. Contrary to ePAM-DMT, the signal generation of the proposed system, termed augmented spectral efficiency discrete multitone (ASE-DMT), occurs in the frequency domain. This results in an improved spectral and energy efficiency. The analytical bit error rate (BER) performance bound of the proposed system is derived and compared with Monte-Carlo simulations. The system performance is shown to offer significant electrical and optical energy savings compared with ePAM-DMT and DC-biased optical orthogonal frequency division multiplexing (DCO-OFDM).

  10. Optical fiber link for transmission of 1-nJ femtosecond laser pulses at 1550 nm.

    Science.gov (United States)

    Eichhorn, Finn; Olsson, Rasmus Kjelsmark; Buron, Jonas C D; Grüner-Nielsen, Lars; Pedersen, Jens Engholm; Jepsen, Peter Uhd

    2010-03-29

    We report on numerical and experimental characterization of the performance of a fiber link optimized for the delivery of sub-100-fs laser pulses at 1550 nm over several meters of fiber. We investigate the power handling capacity of the link, and demonstrate all-fiber delivery of 1-nJ pulses over a distance of 5.3 m. The fiber link consists of dispersion-compensating fiber (DCF) and standard single-mode fiber. The optical pulses at different positions in the fiber link are measured using frequency-resolved optical gating (FROG). The results are compared with numerical simulations of the pulse propagation based on the generalized nonlinear Schrödinger equation. The high input power capacity of the fiber link allows the splitting and distribution of femtosecond pulses to an array of fibers with applications in multi-channel fiber-coupled terahertz time-domain spectroscopy and imaging systems. We demonstrate THz pulse generation and detection using a distributed fiber link with 32 channels and 2.6 nJ input pulse energy.

  11. Real-time dual-polarization transmission based on hybrid optical wireless communications

    Science.gov (United States)

    Sousa, Artur N.; Alimi, Isiaka A.; Ferreira, Ricardo M.; Shahpari, Ali; Lima, Mário; Monteiro, Paulo P.; Teixeira, António L.

    2018-01-01

    We present experimental work on a gigabit-capable and long-reach hybrid coherent UWDM-PON plus FSO system for supporting different applications over the same fiber infrastructure in the mobile backhaul (MBH) networks. Also, for the first time, we demonstrate a reconfigurable real-time DSP transmission/reception of DP-QPSK signals over standard single-mode fiber (SSMF) and FSO links. The receiver presented is based on a commercial field-programmable gate array (FPGA). The considered communication links are based on 20 UDWDM channels with 625 Mbaud and 2.5 GHz channel spacing. We are able to demonstrate the lowest sampling rate required for digital coherent PON by employing four 1.25 Gsa/s ADCs using an electrical front-end receiver that offers only 1 GHz analog bandwidth. We achieved this by implementing a phase and polarization diversity coherent receiver combined with the DP-QPSK modulation formats. The system performance is estimated in terms of receiver sensitivity. The results show the viability of coherent PON and flexible dual-polarization supported by software-defined transceivers for the MBH.

  12. System tests of radiation hard optical links for the ATLAS semiconductor tracker

    International Nuclear Information System (INIS)

    Charlton, D.G.; Dowell, J.D.; Homer, R.J.; Jovanovic, P.; Kenyon, I.R.; Mahout, G.; Shaylor, H.R.; Wilson, J.A.; Rudge, A.; Fopma, J.; Mandic, I.; Nickerson, R.B.; Shield, P.; Wastie, R.; Weidberg, A.R.; Eek, L.-O.; Go, A.; Lund-Jensen, B.; Pearce, M.; Soederqvist, J.; Morrissey, M.; White, D.J.

    2000-01-01

    A prototype optical data and Timing, Trigger and Control transmission system based on LEDs and PIN-diodes has been constructed. The system would be suitable in terms of radiation hardness and radiation length for use in the ATLAS SemiConductor Tracker. Bit error rate measurements were performed for the data links and for the links distributing the Timing, Trigger and Control data from the counting room to the front-end modules. The effects of cross-talk between the emitters and receivers were investigated. The advantages of using Vertical Cavity Surface Emitting Lasers (VCSELs) instead of LEDs are discussed

  13. Towards convergence of wireless and wireline signal transport in broadband access networks

    DEFF Research Database (Denmark)

    Yu, Xianbin; Prince, Kamau; Tafur Monroy, Idelfonso

    2010-01-01

    Hybrid optical wireless access networks are to play an important role in the realization of the vision of delivery of broadband services to the end-user any time, anywhere and at affordable costs. We present results of experiments conducted over a field deployed optical fibre links we successfull...... demonstrated converged wireless and wireline signal transport over a common fibre infrastructure. The type of signal used in this field deployed experiments cover WiMax, Impulse-radio ultra-wideband (UWB) and coherent transmission of baseband QPSK and radio-over-fibre signals....

  14. Quality Assurance Programme for the Environmental Testing of the CMS Tracker Optical Links

    CERN Document Server

    Gill, K; Troska, Jan K; Vasey, F; Zanet, A

    2001-01-01

    The QA programme is reviewed for the environmental compliance tests of commercial off-the-shelf (COTS) components for the CMS Tracker Optical link system. These environmental tests will take place in the pre-production and final production phases of the project and will measure radiation resistance, component lifetime, and sensitivity to magnetic fields. The evolution of the programme from small-scale prototype tests to the final pre-production manufacturing tests is outlined and the main environmental effects expected for optical links operating within the Tracker are summarised. A special feature of the environmental QA programme is the plan for Advance Validation Tests (AVT's) developed in close collaboration with the various industrial partners. AVT procedures involve validation of a relatively small set of basic samples in advance of the full production of the corresponding batch of devices. Only those lots that have been confirmed as sufficiently rad-tolerant will be purchased and used in the final prod...

  15. Femtosecond stabilization of optical fiber links based on RF power detection

    International Nuclear Information System (INIS)

    Lamb, Thorsten

    2011-01-01

    X-ray light sources like the free electron laser FLASH in Hamburg or the future XFEL generate light pulses with durations in the order of a few ten femtoseconds. To fulfill the requirements for the synchronisation of various components on this timescale, optical synchronisation systems are already successfully used. In this diploma thesis a novel photodiode-based, detection principle for the measurement of drifts in the optical links of such a synchronisation system is developed. The detection principle is nearly drift-free and highly robust. It is demonstrated that the long term stability of the assembled detector over 33 h is below 5 fs (peak to peak) at a standard deviation of 0.86 fs. Furthermore, an active stabilisation of a fibre link using this detector is successfully achieved. (orig.)

  16. Digital coherent receiver for phase modulated radio-over-fibre optical links

    DEFF Research Database (Denmark)

    Zibar, Darko; Yu, Xianbin; Peucheret, Christophe

    2009-01-01

    A novel digital signal processing-based coherent receiver for phase-modulated radio-over-fiber (RoF) optical links is presented and demonstrated experimentally. Error-free demodulation of 50-Mbaud binary phase-shift keying (BPSK) and quadrature phase-shift keying data signal modulated on a 5-GHz...... radio-frequency (RF) carrier is experimentally demonstrated using the proposed digital coherent receiver. Additionally, a wavelength-division-multiplexing (WDM) phase-modulated RoF optical link is experimentally demonstrated. A 3 x50 Mb/s WDM transmission of a BPSK modulated 5-GHz RF carrier is achieved...... over 25 km for the WDM channel spacing of 12.5 and 25 GHz, respectively....

  17. Data transmission with twisted light through a free-space to fiber optical communication link

    International Nuclear Information System (INIS)

    Brüning, Robert; Duparré, Michael; Ndagano, Bienvenu; McLaren, Melanie; Forbes, Andrew; Schröter, Siegmund; Kobelke, Jens

    2016-01-01

    Mode division multiplexing (MDM), where information is transmitted in the spatial modes of light, is mooted as a future technology with which to transmit large bits of information. However, one of the key issues in optical communication lies in connecting free-space to optical fiber networks, otherwise known as the ‘last mile’ problem. This is particularly problematic for MDM as the eigenmodes of free-space and fibers are in general not the same. Here we demonstrate a data transmission scheme across a free-space and fiber link using twisted light in the form of Laguerre–Gaussian (LG) azimuthal modes. As a proof-of-principle we design and implement a custom fiber where the supported LG modes can be grouped into five non-degenerate sets, and successfully transmit a gray-scale image across the composite link using one mode from each group, thereby ensuring minimal crosstalk. (letter)

  18. Quality Assurance Programme for the Environmental Testing of the CMS Tracker Optical Links

    OpenAIRE

    Gill, K; Grabit, R; Troska, Jan K; Vasey, F; Zanet, A

    2001-01-01

    The QA programme is reviewed for the environmental compliance tests of commercial off-the-shelf (COTS) components for the CMS Tracker Optical link system. These environmental tests will take place in the pre-production and final production phases of the project and will measure radiation resistance, component lifetime, and sensitivity to magnetic fields. The evolution of the programme from small-scale prototype tests to the final pre-production manufacturing tests is outlined and the main env...

  19. Mountain-top-to-valley optical link demonstration as part of a miniature terminal development

    Science.gov (United States)

    Mosberger, Martin; Dreischer, Thomas; Bacher, Michael

    2013-03-01

    A mountain-top-to-valley optical link demonstration was performed in Switzerland between Säntis mountain, 2'502m altitude, and Dübendorf airfield, 448m altitude. The link distance at very low elevation angle of 2° was 55km. Main goal was to evaluate an optical communication system for LEO-to-Ground links in realistic atmospheric conditions, though worst case, comprising the impact on data throughput and on pointing acquisition and tracking performance. Three wavelengths were tested simultaneously, a downlink at both, 1550nm and 808nm together with a 1064nm uplink, thus allowing for comparison of atmospheric transmission impact over a wide wavelength range. Alongside, all transmitters were designed to be eye-safe. The mountain top transmitter was installed inside a service building and the 60cm receiver telescope on the airfield was placed in an open stand. The link demonstration forms part of an on-going development activity started at RUAG Space with support from ESA in 2010. This activity is currently in the Engineering Model phase and aims at the Flight Model to be ready in 2016. Goal is to develop an optical downlink terminal that primarily addresses the needs of the emerging market of small satellites, the optical ground terminal and the ground network topology. The overall test approach is presented and explained together with a summary of all activities performed. Test results are presented and the discovered issues are addressed. Furthermore, a general overview is provided on the development activity and its current status.

  20. Limited Evaluation of an 802.11b Air-to-Air Wireless Data Link (Project Have HALO II)

    National Research Council Canada - National Science Library

    Volesky, Robert A; Geitgey, Jason W; Vap, Jason C; Creviston, Douglas O; Kikuchi, Morikazu

    2007-01-01

    ... and 1.58 Watt effective isotropic radiated power. The test team also demonstrated the capability of transmitting still photos, streaming video, pre-recorded video and text files across the data link...

  1. Linearized Optically Phase-Modulated Fiber Optic Links for Microwave Signal Transport

    Science.gov (United States)

    2009-03-03

    detectors (with internal 50- Ohm resistors) capable of 40-mA dc current per detector. With this link, the linearized SFDR would improve to 133 dB/Hz4/5...the IF) limitation on the signal. All calculations consider the 3dB power loss from the hybrid combiner and 6dB loss from parallel 50- Ohm resistors...283. [25] M. Nazarathy, J. Berger, A. Ley , I. Levi, and Y. Kagan, “Externally Modulated 80 Channel Am Catv Fiber-to-feeder Distribution System Over

  2. Multiband Carrierless Amplitude Phase Modulation for High Capacity Optical Data Links

    DEFF Research Database (Denmark)

    Iglesias Olmedo, Miguel; Zuo, Tianjian; Jensen, Jesper Bevensee

    2014-01-01

    Short range optical data links are experiencing bandwidth limitations making it very challenging to cope with the growing data transmission capacity demands. Parallel optics appears as a valid short-term solution. It is, however, not a viable solution in the long-term because of its complex optical...... and bandwidth limitations and reduces the complexity of the transceiver. We report on numerical simulations and experimental demonstrations with capacity beyond 100 Gb/s transmission using a single externally modulated laser (EML). In addition, an extensive comparison with conventional CAP is also provided....... The reported experiment uses MultiCAP to achieve 102.4 Gb/s transmission, corresponding to a data payload of 95.2 Gb/s error free transmission by using a 7% forward error correction (FEC) code. The signal is successfully recovered after 15 km of standard single mode fiber (SSMF) in a system limited by a 3 d...

  3. A home-built digital optical MRI console using high-speed serial links.

    Science.gov (United States)

    Tang, Weinan; Wang, Weimin; Liu, Wentao; Ma, Yajun; Tang, Xin; Xiao, Liang; Gao, Jia-Hong

    2015-08-01

    To develop a high performance, cost-effective digital optical console for scalable multichannel MRI. The console system was implemented with flexibility and efficiency based on a modular architecture with distributed pulse sequencers. High-speed serial links were optimally utilized to interconnect the system, providing fast digital communication with a multi-gigabit data rate. The conventional analog radio frequency (RF) chain was replaced with a digital RF manipulation. The acquisition electronics were designed in close proximity to RF coils and preamplifiers, using a digital optical link to transmit the MR signal. A prototype of the console was constructed with a broad frequency range from direct current to 100 MHz. A temporal resolution of 1 μs was achieved for both the RF and gradient operations. The MR signal was digitized in the scanner room with an overall dynamic range between 16 and 24 bits and was transmitted to a master controller over a duplex optic fiber with a high data rate of 3.125 gigabits per second. High-quality phantom and human images were obtained using the prototype on both 0.36T and 1.5T clinical MRI scanners. A homemade digital optical MRI console with high-speed serial interconnection has been developed to better serve imaging research and clinical applications. © 2014 Wiley Periodicals, Inc.

  4. Probabilistic Model for Free-Space Optical Links Under Continental Fog Conditions

    Directory of Open Access Journals (Sweden)

    Marzuki

    2010-09-01

    Full Text Available The error characteristics of a free-space optical (FSO channel are significantly different from the fiber based optical links and thus require a deep physical understanding of the propagation channel. In particular different fog conditions greatly influence the optical transmissions and thus a channel model is required to estimate the detrimental fog effects. In this paper we shall present the probabilistic model for radiation fog from the measured data over a 80 m FSO link installed at Graz, Austria. The fog events are classified into thick fog, moderate fog, light fog and general fog based on the international code of visibility range. We applied some probability distribution functions (PDFs such as Kumaraswamy, Johnson SB and Logistic distribution, to the actual measured optical attenuations. The performance of each distribution is evaluated by Q-Q and P-P plots. It is found that Kumaraswamy distribution is the best fit for general fog, while Logistic distribution is the optimum choice for thick fog. On the other hand, Johnson SB distribution best fits the moderate and light fog related measured attenuation data. The difference in these probabilistic models and the resultant variation in the received signal strength under different fog types needs to be considered in designing an efficient FSO system.

  5. Design and Performance of a PCI Interface with four 2 Gbit/s Serial Optical Links

    CERN Document Server

    Haas, S; Iwanski, W; 10th Workshop on Electronics for LHC and Future Experiments

    2004-01-01

    A reconfigurable PCI interface card (FILAR) with four on-board high-speed serial optical links has been developed for application in DAQ and test systems. FILAR cards, installed in low cost PCs, are currently being used in the combined test-beam of the ATLAS experiment at CERN as well as in several laboratory set-ups. The hardware and firmware design of the module and results from performance measurements are presented. The four on-board 2 Gbit/s serial optical links conform to the S-LINK specification and are compatible with the Readout Link (ROL) implementation for the ATLAS experiment. The board design is largely based on FPGAs and the firmware uses a commercial 64-bit/66 MHz PCI IP core for the bus interface. Different firmware versions were developed which can be used to configure the hardware as either a data source or a destination card. Design optimizations have been made during the development cycle of the firmware to maximize the data throughput and reduce the PCI bus overhead as well as the CPU loa...

  6. Wireless Access

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Wireless Access. Wireless connect to the Base station. Easy and Convenient access. Costlier as compared to the wired technology. Reliability challenges. We see it as a complementary technology to the DSL.

  7. 4.8 Gbit/s 16-QAM-OFDM transmission based on compact 450-nm laser for underwater wireless optical communication

    KAUST Repository

    Oubei, Hassan M.

    2015-08-26

    We experimentally demonstrate an underwater wireless optical communications (UWOC) employing 450-nm TO-9 packaged and fiberpigtailed laser diode (LD) directly encoded with an orthogonal frequency division multiplexed quadrature amplitude modulation (QAM-OFDM) data. A record data rate of up to 4.8 Gbit/s over 5.4-m transmission distance is achieved. By encoding the full 1.2-GHz bandwidth of the 450-nm LD with a 16-QAM-OFDM data, an error vector magnitude (EVM) of 16.5%, a signal-to-noise ratio (SNR) of 15.63 dB and a bit error rate (BER) of 2.6 × 10-3, well pass the forward error correction (FEC) criterion, were obtained. © 2015 Optical Society of America.

  8. Data transmission optical link for LLRF TESLA project part I: hardware structure of OPT0 module

    Science.gov (United States)

    Pozniak, Krzysztof T.; Romaniuk, Ryszard S.; Jalmuzna, Wojciech; Olowski, Krzysztof; Perkuszewski, Karol; Zielinski, Jerzy; Kierzkowski, Krzysztof

    2006-03-01

    It may be predicted now, even assuming a very conservative approach, that the next generation of the Low Level RF control systems for future accelerators will use extensively such technologies like: very fast programmable circuits equipped with DSP, embedded PC and optical communication I/O functionalities, as well as multi-gigabit optical transmission of measurement data and control signals. The paper presents the idea and realization of a gigabit synchronous data distributor designed to work in the LLRF control system of TESLA technology based X-ray FEL. The design bases on a relatively simple and cheap FPGA chip Cyclone. Commercially available SERDES (serializer/deserializer) and optical transceiver chips were applied. The optoelectronic module is embedded on the main LLRF BMB (backbone mother board). The MB provides communication with the outside computer control system, programmable chip configuration, integration with other functional modules and power supply. The hardware implementation is here described and the used software for BER (bit-error-rate) testing of the multi-gigabit optical link. The measurement results are presented. The appendix contains a comparison between the available protocols of serial data transmission for FPGA technology. This paper is a partial contribution to the next version of the SIMCON system which is expected to be released this year. The SIMCON, ver 3.0 will contain 8 channels and multi-gigabit optical transmission capability. It will be a fully modular construction.

  9. SDN control of optical nodes in metro networks for high capacity inter-datacentre links

    Science.gov (United States)

    Magalhães, Eduardo; Perry, Philip; Barry, Liam

    2017-11-01

    Worldwide demand for bandwidth has been growing fast for some years and continues to do so. To cover this, mega datacentres need scalable connectivity to provide rich connectivity to handle the heavy traffic across them. Therefore, hardware infrastructures must be able to play different roles according to service and traffic requirements. In this context, software defined networking (SDN) decouples the network control and forwarding functions enabling the network control to become directly programmable and the underlying infrastructure to be abstracted for applications and network services. In addition, elastic optical networking (EON) technologies enable efficient spectrum utilization by allocating variable bandwidth to each user according to their actual needs. In particular, flexible transponders and reconfigurable optical add/drop multiplexers (ROADMs) are key elements since they can offer degrees of freedom to self adapt accordingly. Thus, it is crucial to design control methods in order to optimize the hardware utilization and offer high reconfigurability, flexibility and adaptability. In this paper, we propose and analyze, using a simulation framework, a method of capacity maximization through optical power profile manipulation for inter datacentre links that use existing metropolitan optical networks by exploiting the global network view afforded by SDN. Results show that manipulating the loss profiles of the ROADMs in the metro-network can yield optical signal-to-noise ratio (OSNR) improvements up to 10 dB leading to an increase in 112% in total capacity.

  10. SmartMIMO: An Energy-Aware Adaptive MIMO-OFDM Radio Link Control for Next-Generation Wireless Local Area Networks

    Directory of Open Access Journals (Sweden)

    Dehaene Wim

    2007-01-01

    Full Text Available Multiantenna systems and more particularly those operating on multiple input and multiple output (MIMO channels are currently a must to improve wireless links spectrum efficiency and/or robustness. There exists a fundamental tradeoff between potential spectrum efficiency and robustness increase. However, multiantenna techniques also come with an overhead in silicon implementation area and power consumption due, at least, to the duplication of part of the transmitter and receiver radio front-ends. Although the area overhead may be acceptable in view of the performance improvement, low power consumption must be preserved for integration in nomadic devices. In this case, it is the tradeoff between performance (e.g., the net throughput on top of the medium access control layer and average power consumption that really matters. It has been shown that adaptive schemes were mandatory to avoid that multiantenna techniques hamper this system tradeoff. In this paper, we derive smartMIMO: an adaptive multiantenna approach which, next to simply adapting the modulation and code rate as traditionally considered, decides packet-per-packet, depending on the MIMO channel state, to use either space-division multiplexing (increasing spectrum efficiency, space-time coding (increasing robustness, or to stick to single-antenna transmission. Contrarily to many of such adaptive schemes, the focus is set on using multiantenna transmission to improve the link energy efficiency in real operation conditions. Based on a model calibrated on an existing reconfigurable multiantenna transceiver setup, the link energy efficiency with the proposed scheme is shown to be improved by up to 30% when compared to nonadaptive schemes. The average throughput is, on the other hand, improved by up to 50% when compared to single-antenna transmission.

  11. SmartMIMO: An Energy-Aware Adaptive MIMO-OFDM Radio Link Control for Next-Generation Wireless Local Area Networks

    Directory of Open Access Journals (Sweden)

    Wim Dehaene

    2007-12-01

    Full Text Available Multiantenna systems and more particularly those operating on multiple input and multiple output (MIMO channels are currently a must to improve wireless links spectrum efficiency and/or robustness. There exists a fundamental tradeoff between potential spectrum efficiency and robustness increase. However, multiantenna techniques also come with an overhead in silicon implementation area and power consumption due, at least, to the duplication of part of the transmitter and receiver radio front-ends. Although the area overhead may be acceptable in view of the performance improvement, low power consumption must be preserved for integration in nomadic devices. In this case, it is the tradeoff between performance (e.g., the net throughput on top of the medium access control layer and average power consumption that really matters. It has been shown that adaptive schemes were mandatory to avoid that multiantenna techniques hamper this system tradeoff. In this paper, we derive smartMIMO: an adaptive multiantenna approach which, next to simply adapting the modulation and code rate as traditionally considered, decides packet-per-packet, depending on the MIMO channel state, to use either space-division multiplexing (increasing spectrum efficiency, space-time coding (increasing robustness, or to stick to single-antenna transmission. Contrarily to many of such adaptive schemes, the focus is set on using multiantenna transmission to improve the link energy efficiency in real operation conditions. Based on a model calibrated on an existing reconfigurable multiantenna transceiver setup, the link energy efficiency with the proposed scheme is shown to be improved by up to 30% when compared to nonadaptive schemes. The average throughput is, on the other hand, improved by up to 50% when compared to single-antenna transmission.

  12. Beam steering application for W-band data links with moving targets in 5G wireless networks

    DEFF Research Database (Denmark)

    Morales Vicente, Alvaro; Rodríguez Páez, Juan Sebastián; Gallardo, Omar

    2017-01-01

    link is evaluated in terms of real-time BER (Bit Error Rate) measurements. The receiver is situated in different positions, and the orientation of the transmitter is changed accordingly. Values below the forward error correction limit for 7% overhead are obtained over a range of 60 cm around a center...

  13. Combined effect of turbulence and aerosol on free-space optical links.

    Science.gov (United States)

    Libich, Jiri; Perez, Joaquin; Zvanovec, Stanislav; Ghassemlooy, Zabih; Nebuloni, Roberto; Capsoni, Carlo

    2017-01-10

    Despite the benefits of free-space optical (FSO) communications, their full utilization is limited by the influence of atmospheric weather conditions, such as fog, turbulence, smoke, snow, etc. In urban environments, additional environmental factors such as smog and dust particles due to air pollution caused by industry and motor vehicles may affect FSO link performance, which has not been investigated in detail yet. Both smog and dust particles cause absorption and scattering of the propagating optical signal, thus resulting in high attenuation. This work investigates the joint impact of atmospheric turbulence and dust particle-imposed scattering on FSO link performance as part of the last-mile access network in urban areas. Propagation of an optical wave is at first analyzed based on the microphysic approach, and the extinction caused by small particles is determined. An experimental measurement campaign using a dedicated test chamber is carried out to assess FSO link performance operating wavelengths of 670 nm and 830 nm and under dust and turbulent conditions. The measured attenuation and the Q factor in terms of the velocity of particle flow and turbulence strength are analyzed. We show that for an airflow of 2 m/s, the Q factor is almost 3.5 higher at the wavelength of 830 nm than at 670 nm. However, for a wavelength of 670 nm, the FSO link is less affected by the increase in airflow compared to 830 nm. The Q factor reduces with turbulence. Under similar turbulence conditions, for ash particles, the Q factor is higher than that of sand particles.

  14. 1.25 Gbit/s bidirectional link in an access network employing a reconfigurable optical add/drop multiplexer and a reflective semiconductor optical amplifier

    NARCIS (Netherlands)

    Urban, P.J.; de Laat, M.M.; Klein, E.J.; Koonen, A.M.J.; Khoe, G.D.; de Waardt, H.; Marciniak, M.; Jaworski, M.; Zdabiwicz, M.

    2008-01-01

    In this paper, we demonstrate symmetrical bidirectional transmission of 1.25 Gbit/s wavelength channels in an access network link employing centralized light generation, colourless optical network unit (ONU) and a reconfigurable optical add/drop multiplexer (ROADM). The architecture of ONU is based

  15. Remote controlled signal conditioner and fiber optic data link system development CPRF (Confinement Physics Research Facility)

    International Nuclear Information System (INIS)

    Schrank, L.S.; Caudill, L.D.; Haberstich, A.; Klare, K.A.; Reass, W.A.

    1989-01-01

    The ZTH reversed-field pinch to be installed in the Confinement Physics Research Facility (CPRF) will produce a significant ambient magnetic field. To avoid ground-loop and other electrical problems, the diagnostics in direct or possible contact with the experiment will be accessed through a fiber optic data way. The frequency-modulated analog links developed for this system have a bandwidth of dc to 100 kHz and a signal-to-noise ratio of better than 60 dB. The fiber optic transmitter units include a signal conditioner and a microprocessor controller. The conditioners can be configured as dc-coupled, low-noise differential amplifiers, or as high-gain, low-drift differential integrators with a very long droop time constant. Magnetic field pickup is minimized by balancing sensitive circuit areas to within 5 mm 2 in all three planes of the PC boards. The gain, offset, and integrator reset are controlled and monitored by the microprocessor, and their status is displayed on the front panel of the transmitter unit. The signal conditioner can be controlled locally, or by way of a fiber optic coupled control network. The system allows fast, convenient, noise-immune control of a large number of signal conditioners from a central host computer. By varying the offset, the computer can verify the operational integrity of the data links. 2 refs., 6 figs

  16. Wireless Distributed Antenna MIMO

    DEFF Research Database (Denmark)

    2015-01-01

    The present disclosure relates to system applications of multicore optical fibers. One embodiment relates to a base transceiver station for a wireless telecommunication system comprising a plurality of antenna units arranged in a MIMO configuration and adapted for transmission and/or reception...

  17. Free-Space Optical Communications Link at 1550-nm using Multiple-Quantum-Well Modulating Retroreflectors in a Marine Environment

    National Research Council Canada - National Science Library

    Rabinovich, W. S; Mahon, R; Burris, H. R; Gilbreath, G. C; Goetz, P. G; Moore, C. I; Stell, M. F; Vilcheck, M. J; Witkowsky, J. L; Swingen, L

    2005-01-01

    A 1550-nm eye-safe, free-space optical communications link is demonstrated at rates up to 5 Mbits/s over a distance of 2 km in the Chesapeake Bay, using quantum-well-based modulating retroreflectors...

  18. DEVELOPMENT OF WIRELESS TECHNIQUES IN DATA AND POWER TRANSMISSION APPLICATION FOR PARTICLE-PHYSICS DETECTORS

    CERN Document Server

    Brenner, R; Dehos, C; De Lurgio, P; Djurcic, Z; Drake, G; Gonzales Gimenez, JL; Gustafsson, L; Kim, DW; Locci, E; Pfeiffer, U; Röhrich, D; Rydberg, D; Schöning, A; Siligaris, A; Soltveit, HK; Ullaland, K; Vincent, P; Vasquez, PR; Wiedner, D; Yang, S

    2017-01-01

    In the WADAPT project described in this Letter of Intent, we propose to develop wireless techniques for data and power transmission in particle-physics detectors. Wireless techniques have developed extremely fast over the last decade and are now mature for being considered as a promising alternative to cables and optical links that would revolutionize the detector design. The WADAPT consortium has been formed to identify the specific needs of different projects that might benefit from wireless techniques with the objective of providing a common platform for research and development in order to optimize effectiveness and cost. The proposed R&D will aim at designing and testing wireless demonstrators for large instrumentation systems.

  19. Synchronous optical transmission data link integrated with FPGA for TESLA FEL SIMCON system: long data vector optical transceiver module tests

    Science.gov (United States)

    Zielinski, Jerzy S.; Pozniak, Krzysztof T.; Romaniuk, Ryszard S.

    2006-10-01

    The X-ray free-electron laser X-FEL that is being planned at the DESY research center in cooperation with European partners will produce high-intensity ultra-short X-ray flashes with the properties of laser light. This new light source, which can only be described in terms of superlatives, will open up a whole range of new possibilities for the natural sciences. It could also offer very promising opportunities for industrial users. SIMCON (SIMulator and CONtroller) is the project of the fast, low latency digital controller dedicated to the LLRF system in VUV FEL experiment. The main purpose of the project is to create a controller to stabilize the vector sum of fields in cavities of one cryo-module in the experiment. The device can be also used as the simulator of the cavity and test bench for other devices. The synchronic, optical link project was made for the accelerator X-FEL laser TESLA, the LLRF control system experiment at DESY, Hamburg. The control and diagnostic data is transmitted up to 2.5Gbit/s through a plastic fiber in a distance up to a few hundred meters. The link is synchronized once after power up, and never resynchronized when data is transmitted with maximum speed. The one way link bit error rate is less then 10 -15. The transceiver component written in VHDL that works in the dedicated Altera® Stratix® GX FPGA circuit. During the work in the PERG laboratory a 2.5Gbit/s serial link with the long vector parallel interface transceiver was created. Long-Data-Vector transceiver transmits 16bit vector each 8ns with 120ns latency.

  20. A paraeducator glove for counting disabled-child behaviors that incorporates a Bluetooth Low Energy wireless link to a smart phone.

    Science.gov (United States)

    Luan, Shiwei; Gude, Dana; Prakash, Punit; Warren, Steve

    2014-01-01

    Behavior tracking with severely disabled children can be a challenge, since dealing directly with a child's behavior is more immediately pressing than the need to record an event for tracking purposes. By the time a paraeducator (`para') is able to break away and record events, behavior counts can be forgotten. This paper presents a paraeducator glove design that can help to track behaviors with minimal distraction by allowing a paraeducator to touch their thumb to one of their other four fingers, where each finger represents a different behavior. Count data are packaged by a microcontroller board on the glove and then sent wirelessly to a smart phone via a Bluetooth Low Energy (BLE) link. A customized BLE profile was designed for this application to promote real-time recording. These data can be forwarded to a database for further analysis. This para glove design addresses basic needs of a wearable device that employs BLE, including local data collection, BLE data transmission, and remote data recording. More functional sensors can be added to this platform to support other wearable scenarios.

  1. Propagation engineering in wireless communications

    CERN Document Server

    Ghasemi, Abdollah; Ghasemi, Farshid

    2016-01-01

    This book covers the basic principles for understanding radio wave propagation for common frequency bands used in radio-communications. This includes achievements and developments in propagation models for wireless communication. This book is intended to bridge the gap between the theoretical calculations and approaches to the applied procedures needed for radio links design in a proper manner. The authors emphasize propagation engineering by giving fundamental information and explain the use of basic principles together with technical achievements. This new edition includes additional information on radio wave propagation in guided media and technical issues for fiber optics cable networks with several examples and problems. This book also includes a solution manual - with 90 solved examples distributed throughout the chapters - and 158 problems including practical values and assumptions.

  2. High power free space optical link for rapid energy and data transmission

    Science.gov (United States)

    Dhadwal, Harbans S.; Rastegar, Jahangir; Feng, Dake; Kwok, Philip

    2016-05-01

    Design and experimental data for a high power laser diode based free space point-to-point optical power/data link is presented. In time critical power up applications, such as providing power and guidance information to a munition shell just prior to deployment, energy of the order of 100 J needs to be transferred in under 10 s. Current inductive technology is slow and broadcasts a radio-frequency signal which is undesirable for stealth operation. Rapid energy transfer times require high irradiance levels at the surface of the photovoltaic cells, typically, exceeding 1000X suns. Through efficient thermal design of heat sinks, high optical to electrical power conversion efficiencies of 50%, which are usually attainable at low power levels of 1 W, are achievable at higher power levels.

  3. JouFLU: upgrades to the fiber linked unit for optical recombination (FLUOR) interferometric beam combiner.

    Science.gov (United States)

    Scott, N. J.; Lhomé, E.; ten Brummelaar, T. A.; Coudé du Foresto, V.; Millan-Gabet, R.; Sturmann, J.; Sturmann, L.

    2014-07-01

    The Fiber Linked Unit for Optical Recombination (FLUOR) is a precision interferometric beam combiner operating at the CHARA Array on Mt. Wilson, CA. It has recently been upgraded as part of a mission known as "Jouvence of FLUOR" or JouFLU. As part of this program JouFLU has new mechanic stages and optical payloads, new alignment systems, and new command/control software. Furthermore, new capabilities have been implemented such as a Fourier Transform Spectrograph (FTS) mode and spectral dispersion mode. These upgrades provide new capabilities to JouFLU as well as improving statistical precision and increasing observing efficiency. With these new systems, measurements of interferometric visibility to the level of 0.1% precision are expected on targets as faint as 6th magnitude in the K band. Here we detail the upgrades of JouFLU and report on its current status.

  4. Sub-cycle QAM modulation for VCSEL-based optical fiber links

    DEFF Research Database (Denmark)

    Pham, Tien-Thang; Rodes Lopez, Roberto; Jensen, Jesper Bevensee

    2013-01-01

    QAM modulation utilizing subcarrier frequency lower than the symbol rate is both theoretically and experimentally investigated. High spectral efficiency and concentration of power in low frequencies make sub-cycle QAM signals attractive for optical fiber links with direct modulated light sources....... Real-time generated 10-Gbps 4-level QAM signal in a 7.5-GHz bandwidth utilizing subcarrier frequency at a half symbol rate was successfully transmitted over 20-km SMF using an un-cooled 1.5-μm VCSEL. Only 2.5-dB fiber transmission power penalty was observed with no equalization applied....

  5. FPGA-based Bit-Error-Rate Tester for SEU-hardened Optical Links

    CERN Document Server

    Detraz, S; Moreira, P; Papadopoulos, S; Papakonstantinou, I; Seif El Nasr, S; Sigaud, C; Soos, C; Stejskal, P; Troska, J; Versmissen, H

    2009-01-01

    The next generation of optical links for future High-Energy Physics experiments will require components qualified for use in radiation-hard environments. To cope with radiation induced single-event upsets, the physical layer protocol will include Forward Error Correction (FEC). Bit-Error-Rate (BER) testing is a widely used method to characterize digital transmission systems. In order to measure the BER with and without the proposed FEC, simultaneously on several devices, a multi-channel BER tester has been developed. This paper describes the architecture of the tester, its implementation in a Xilinx Virtex-5 FPGA device and discusses the experimental results.

  6. Investigation of coherent receiver designs in high-speed optical inter-satellite links using digital signal processing

    Science.gov (United States)

    Schaefer, S.; Gregory, M.; Rosenkranz, W.

    2017-09-01

    Due to higher data rates, better data security and unlicensed spectral usage optical inter-satellite links (OISL) offer an attractive alternative to conventional RF-communication. However, the very high transmission distances necessitate an optical receiver design enabling high receiver sensitivity which requires careful carrier synchronization and a quasi-coherent detection scheme.

  7. Ergodic Capacity Analysis of Free-Space Optical Links with Nonzero Boresight Pointing Errors

    KAUST Repository

    Ansari, Imran Shafique

    2015-04-01

    A unified capacity analysis of a free-space optical (FSO) link that accounts for nonzero boresight pointing errors and both types of detection techniques (i.e. intensity modulation/ direct detection as well as heterodyne detection) is addressed in this work. More specifically, an exact closed-form expression for the moments of the end-to-end signal-to-noise ratio (SNR) of a single link FSO transmission system is presented in terms of well-known elementary functions. Capitalizing on these new moments expressions, we present approximate and simple closedform results for the ergodic capacity at high and low SNR regimes. All the presented results are verified via computer-based Monte-Carlo simulations.

  8. Analysis of fog effects on terrestrial Free Space optical communication links

    KAUST Repository

    Esmail, Maged Abdullah

    2016-07-26

    In this paper, we consider and examine fog measurement data, coming from several locations in Europe and USA, and attempt to derive a unified model for fog attenuation in free space optics (FSO) communication links. We evaluate and compare the performance of our proposed model to that of many well-known alternative models. We found that our proposed model, achieves an average RMSE that outperforms them by more than 9 dB. Furthermore, we have studied the performance of the FSO system using different performance metrics such as signal-to-noise (SNR) ratio, bit error rate (BER), and channel capacity. Our results show that FSO is a short range technology. Therefore, FSO is expected to find its place in future networks that will have small cell size, i.e., <1 km diameter. Moreover, our investigation shows that under dense fog, it is difficult to maintain a communications link because of the high signal attenuation, which requires switching the communications to RF backup. Our results show that increasing the transmitted power will improve the system performance under light fog. However, under heavy fog, the effect is minor. To enhance the system performance under low visibility range, multi-hop link is used which can enhance the power budget by using short segments links. Using 22 dBm transmitted power, we obtained BER=10-3 over 1 km link length with 600 m visibility range which corresponds to light fog. However, under lower visibility range equals 40 m that corresponds to dense fog, we obtained the same BER but over 200 m link length. © 2016 IEEE.

  9. Limitations in distance and frequency due to chromatic dispersion in fibre-optic microwave and millimeter-wave links

    DEFF Research Database (Denmark)

    Gliese, Ulrik Bo; Nielsen, Søren Nørskov; Nielsen, Søren Nørskov

    1996-01-01

    Chromatic dispersion significantly limits the distance and/or frequency in fibre-optic microwave and millimeter-wave links based on direct detection due to a decrease of the carrier to noise ratio. The limitations in links based on coherent remote heterodyne detection, however, are far less signi...

  10. Limitations in distance and frequency due to chromatic dispersion in fibre-optic microwave and millimeter-wave links

    OpenAIRE

    Gliese, Ulrik Bo; Nielsen, Søren Nørskov; Nielsen, Søren Nørskov

    1996-01-01

    Chromatic dispersion significantly limits the distance and/or frequency in fibre-optic microwave and millimeter-wave links based on direct detection due to a decrease of the carrier to noise ratio. The limitations in links based on coherent remote heterodyne detection, however, are far less significant, and are primarily due to an increase of the phase noise

  11. Design and optimization of a fiber optic data link for new generation on-board SAR processing architectures

    Science.gov (United States)

    Ciminelli, Caterina; Dell'Olio, Francesco; Armenise, Mario N.; Iacomacci, Francesco; Pasquali, Franca; Formaro, Roberto

    2017-11-01

    A fiber optic digital link for on-board data handling is modeled, designed and optimized in this paper. Design requirements and constraints relevant to the link, which is in the frame of novel on-board processing architectures, are discussed. Two possible link configurations are investigated, showing their advantages and disadvantages. An accurate mathematical model of each link component and the entire system is reported and results of link simulation based on those models are presented. Finally, some details on the optimized design are provided.

  12. A full-duplex CATV/wireless-over-fiber lightwave transmission system.

    Science.gov (United States)

    Li, Chung-Yi; Lu, Hai-Han; Ying, Cheng-Ling; Cheng, Chun-Jen; Lin, Che-Yu; Wan, Zhi-Wei; Chen, Jian-Hua

    2015-04-06

    A full-duplex CATV/wireless-over-fiber lightwave transmission system consisting of one broadband light source (BLS), two optical interleavers (ILs), one intensity modulator, and one phase modulator is proposed and experimentally demonstrated. The downstream light is optically promoted from 10Gbps/25GHz microwave (MW) data signal to 10Gbps/100GHz and 10Gbps/50GHz millimeter-wave (MMW) data signals in fiber-wireless convergence, and intensity-modulated with 50-550 MHz CATV signal. For up-link transmission, the downstream light is phase-remodulated with 10Gbps/25GHz MW data signal in fiber-wireless convergence. Over a 40-km single-mode fiber (SMF) and a 10-m radio frequency (RF) wireless transport, bit error rate (BER), carrier-to-noise ratio (CNR), composite second-order (CSO), and composite triple-beat (CTB) are observed to perform well in such full-duplex CATV/wireless-over-fiber lightwave transmission systems. This full-duplex 100-GHz/50-GHz/25-GHz/550-MHz lightwave transmission system is an attractive alternative. This transmission system not only presents its advancement in the integration of fiber backbone and CATV/wireless feeder networks, but also it provides the advantages of a communication channel for higher data rates and bandwidth.

  13. Simulink models for performance analysis of high speed DQPSK modulated optical link

    Energy Technology Data Exchange (ETDEWEB)

    Sharan, Lucky, E-mail: luckysharan@pilani.bits-pilani.ac.in; Rupanshi,, E-mail: f2011222@pilani.bits-pilani.ac.in; Chaubey, V. K., E-mail: vkc@pilani.bits-pilani.ac.in [EEE Department, BITS-Pilani, Rajasthan, 333031 (India)

    2016-03-09

    This paper attempts to present the design approach for development of simulation models to study and analyze the transmission of 10 Gbps DQPSK signal over a single channel Peer to Peer link using Matlab Simulink. The simulation model considers the different optical components used in link design with their behavior represented initially by theoretical interpretation, including the transmitter topology, Mach Zehnder Modulator(MZM) module and, the propagation model for optical fibers etc. thus allowing scope for direct realization in experimental configurations. It provides the flexibility to incorporate the various photonic components as either user-defined or fixed and, can also be enhanced or removed from the model as per the design requirements. We describe the detailed operation and need of every component model and its representation in Simulink blocksets. Moreover the developed model can be extended in future to support Dense Wavelength Division Multiplexing (DWDM) system, thereby allowing high speed transmission with N × 40 Gbps systems. The various compensation techniques and their influence on system performance can be easily investigated by using such models.

  14. Simulink models for performance analysis of high speed DQPSK modulated optical link

    Science.gov (United States)

    Sharan, Lucky; Rupanshi, Chaubey, V. K.

    2016-03-01

    This paper attempts to present the design approach for development of simulation models to study and analyze the transmission of 10 Gbps DQPSK signal over a single channel Peer to Peer link using Matlab Simulink. The simulation model considers the different optical components used in link design with their behavior represented initially by theoretical interpretation, including the transmitter topology, Mach Zehnder Modulator(MZM) module and, the propagation model for optical fibers etc. thus allowing scope for direct realization in experimental configurations. It provides the flexibility to incorporate the various photonic components as either user-defined or fixed and, can also be enhanced or removed from the model as per the design requirements. We describe the detailed operation and need of every component model and its representation in Simulink blocksets. Moreover the developed model can be extended in future to support Dense Wavelength Division Multiplexing (DWDM) system, thereby allowing high speed transmission with N × 40 Gbps systems. The various compensation techniques and their influence on system performance can be easily investigated by using such models.

  15. A Wireless Sensor Network for Growth Environment Measurement and Multi-Band Optical Sensing to Diagnose Tree Vigor.

    Science.gov (United States)

    Kameoka, Shinichi; Isoda, Shuhei; Hashimoto, Atsushi; Ito, Ryoei; Miyamoto, Satoru; Wada, Genki; Watanabe, Naoki; Yamakami, Takashi; Suzuki, Ken; Kameoka, Takaharu

    2017-04-27

    We have tried to develop the guidance system for farmers to cultivate using various phenological indices. As the sensing part of this system, we deployed a new Wireless Sensor Network (WSN). This system uses the 920 MHz radio wave based on the Wireless Smart Utility Network that enables long-range wireless communication. In addition, the data acquired by the WSN were standardized for the advanced web service interoperability. By using these standardized data, we can create a web service that offers various kinds of phenological indices as secondary information to the farmers in the field. We have also established the field management system using thermal image, fluorescent and X-ray fluorescent methods, which enable the nondestructive, chemical-free, simple, and rapid measurement of fruits or trees. We can get the information about the transpiration of plants through a thermal image. The fluorescence sensor gives us information, such as nitrate balance index (NBI), that shows the nitrate balance inside the leaf, chlorophyll content, flavonol content and anthocyanin content. These methods allow one to quickly check the health of trees and find ways to improve the tree vigor of weak ones. Furthermore, the fluorescent x-ray sensor has the possibility to quantify the loss of minerals necessary for fruit growth.

  16. A Wireless Sensor Network for Growth Environment Measurement and Multi-Band Optical Sensing to Diagnose Tree Vigor

    Science.gov (United States)

    Kameoka, Shinichi; Isoda, Shuhei; Hashimoto, Atsushi; Ito, Ryoei; Miyamoto, Satoru; Wada, Genki; Watanabe, Naoki; Yamakami, Takashi; Suzuki, Ken; Kameoka, Takaharu

    2017-01-01

    We have tried to develop the guidance system for farmers to cultivate using various phenological indices. As the sensing part of this system, we deployed a new Wireless Sensor Network (WSN). This system uses the 920 MHz radio wave based on the Wireless Smart Utility Network that enables long-range wireless communication. In addition, the data acquired by the WSN were standardized for the advanced web service interoperability. By using these standardized data, we can create a web service that offers various kinds of phenological indices as secondary information to the farmers in the field. We have also established the field management system using thermal image, fluorescent and X-ray fluorescent methods, which enable the nondestructive, chemical-free, simple, and rapid measurement of fruits or trees. We can get the information about the transpiration of plants through a thermal image. The fluorescence sensor gives us information, such as nitrate balance index (NBI), that shows the nitrate balance inside the leaf, chlorophyll content, flavonol content and anthocyanin content. These methods allow one to quickly check the health of trees and find ways to improve the tree vigor of weak ones. Furthermore, the fluorescent x-ray sensor has the possibility to quantify the loss of minerals necessary for fruit growth. PMID:28448452

  17. A Wireless Sensor Network for Growth Environment Measurement and Multi-Band Optical Sensing to Diagnose Tree Vigor

    Directory of Open Access Journals (Sweden)

    Shinichi Kameoka

    2017-04-01

    Full Text Available We have tried to develop the guidance system for farmers to cultivate using various phenological indices. As the sensing part of this system, we deployed a new Wireless Sensor Network (WSN. This system uses the 920 MHz radio wave based on the Wireless Smart Utility Network that enables long-range wireless communication. In addition, the data acquired by the WSN were standardized for the advanced web service interoperability. By using these standardized data, we can create a web service that offers various kinds of phenological indices as secondary information to the farmers in the field. We have also established the field management system using thermal image, fluorescent and X-ray fluorescent methods, which enable the nondestructive, chemical-free, simple, and rapid measurement of fruits or trees. We can get the information about the transpiration of plants through a thermal image. The fluorescence sensor gives us information, such as nitrate balance index (NBI, that shows the nitrate balance inside the leaf, chlorophyll content, flavonol content and anthocyanin content. These methods allow one to quickly check the health of trees and find ways to improve the tree vigor of weak ones. Furthermore, the fluorescent x-ray sensor has the possibility to quantify the loss of minerals necessary for fruit growth.

  18. Compact wideband CMOS receiver frontends for wireless communication

    NARCIS (Netherlands)

    Blaakmeer, S.C.

    2010-01-01

    Abstract Wireless communication is an integral part of our daily life, the mobile phone is an example of a very popular wireless communication device. A communication link consists of a transmitter, a receiver and the transmission medium, which air or vacuum for a wireless link. Part of the receiver

  19. Modelling of 10 Gbps Free Space Optics Communication Link Using Array of Receivers in Moderate and Harsh Weather Conditions

    Science.gov (United States)

    Gupta, Amit; Shaina, Nagpal

    2017-08-01

    Intersymbol interference and attenuation of signal are two major parameters affecting the quality of transmission in Free Space Optical (FSO) Communication link. In this paper, the impact of these parameters on FSO communication link is analysed for delivering high-quality data transmission. The performance of the link is investigated under the influence of amplifier in the link. The performance parameters of the link like minimum bit error rate, received signal power and Quality factor are examined by employing erbium-doped fibre amplifier in the link. The effects of amplifier are visualized with the amount of received power. Further, the link is simulated for moderate weather conditions at various attenuation levels on transmitted signal. Finally, the designed link is analysed in adverse weather conditions by using high-power laser source for optimum performance.

  20. Demonstration and Comparison Study for V- and W-Band Real-Time High-Definition Video Delivery in Diverse Fiber-Wireless Infrastructure

    DEFF Research Database (Denmark)

    Lebedev, Alexander; Vegas Olmos, Juan José; Pang, Xiaodan

    2013-01-01

    . For the W-band, experimental assessment of passive and active approaches for implementation of remote antenna units is reported. The bit error rate performance of the optical and wireless channels is reported. A successful transmission of real-time uncompressed high-definition video in the V- and W......This article experimentally demonstrates uncompressed high-definition video distribution in V-band (50–75 GHz) and W-band (75–110 GHz) fiber-wireless links achieving 3 m of wireless transmission in both cases. Access architecture is experimentally emulated by deploying single/multi-mode fibers...

  1. 4.8 Gbit/s 16-QAM-OFDM transmission based on compact 450-nm laser for underwater wireless optical communication.

    Science.gov (United States)

    Oubei, Hassan M; Duran, Jose R; Janjua, Bilal; Wang, Huai-Yung; Tsai, Cheng-Ting; Chi, Yu-Cheih; Ng, Tien Khee; Kuo, Hao-Chung; He, Jr-Hau; Alouini, Mohamed-Slim; Lin, Gong-Ru; Ooi, Boon S

    2015-09-07

    We experimentally demonstrate an underwater wireless optical communications (UWOC) employing 450-nm TO-9 packaged and fiber-pigtailed laser diode (LD) directly encoded with an orthogonal frequency division multiplexed quadrature amplitude modulation (QAM-OFDM) data. A record data rate of up to 4.8 Gbit/s over 5.4-m transmission distance is achieved. By encoding the full 1.2-GHz bandwidth of the 450-nm LD with a 16-QAM-OFDM data, an error vector magnitude (EVM) of 16.5%, a signal-to-noise ratio (SNR) of 15.63 dB and a bit error rate (BER) of 2.6 × 10(-3), well pass the forward error correction (FEC) criterion, were obtained.

  2. Wireless virtualization

    CERN Document Server

    Wen, Heming; Le-Ngoc, Tho

    2013-01-01

    This SpringerBriefs is an overview of the emerging field of wireless access and mobile network virtualization. It provides a clear and relevant picture of the current virtualization trends in wireless technologies by summarizing and comparing different architectures, techniques and technologies applicable to a future virtualized wireless network infrastructure. The readers are exposed to a short walkthrough of the future Internet initiative and network virtualization technologies in order to understand the potential role of wireless virtualization in the broader context of next-generation ubiq

  3. Fiber wireless networks

    Science.gov (United States)

    Nirmalathas, A.; Bakaul, M.; Lim, C.; Novak, D.; Waterhouse, R.

    2005-11-01

    Broadband wireless networks based on a number of new frequency windows at higher microwave and millimeter-wave frequencies have been actively pursued to provide ultra-high bandwidth services over a wireless networks. These networks will have a large number of antenna base-stations with high throughput. Significant reductions in antenna base-station complexity can be achieved if most of the signal routing and switching functions centralized at a central office in the network. In such a network, fiber feed networks can be effectively deployed to provide high bandwidth interconnections between multiple antenna base-stations and the central office. With wavelength division multiplexing, efficient optical fiber feed network architectures could be realised to provide interconnection to a large number of antenna base-stations. In this paper, we present an over view of our recent research into system technologies for fiber wireless networks.

  4. Wireless telecommunication systems

    CERN Document Server

    Terré, Michel; Vivier, Emmanuelle

    2013-01-01

    Wireless telecommunication systems generate a huge amount of interest. In the last two decades, these systems have experienced at least three major technological leaps, and it has become impossible to imagine how society was organized without them. In this book, we propose a macroscopic approach on wireless systems, and aim at answering key questions about power, data rates, multiple access, cellular engineering and access networks architectures.We present a series of solved problems, whose objective is to establish the main elements of a global link budget in several radiocommunicati

  5. Investigation on iterative multiuser detection physical layer network coding in two-way relay free-space optical links with turbulences and pointing errors.

    Science.gov (United States)

    Abu-Almaalie, Zina; Ghassemlooy, Zabih; Bhatnagar, Manav R; Le-Minh, Hoa; Aslam, Nauman; Liaw, Shien-Kuei; Lee, It Ee

    2016-11-20

    Physical layer network coding (PNC) improves the throughput in wireless networks by enabling two nodes to exchange information using a minimum number of time slots. The PNC technique is proposed for two-way relay channel free space optical (TWR-FSO) communications with the aim of maximizing the utilization of network resources. The multipair TWR-FSO is considered in this paper, where a single antenna on each pair seeks to communicate via a common receiver aperture at the relay. Therefore, chip interleaving is adopted as a technique to separate the different transmitted signals at the relay node to perform PNC mapping. Accordingly, this scheme relies on the iterative multiuser technique for detection of users at the receiver. The bit error rate (BER) performance of the proposed system is examined under the combined influences of atmospheric loss, turbulence-induced channel fading, and pointing errors (PEs). By adopting the joint PNC mapping with interleaving and multiuser detection techniques, the BER results show that the proposed scheme can achieve a significant performance improvement against the degrading effects of turbulences and PEs. It is also demonstrated that a larger number of simultaneous users can be supported with this new scheme in establishing a communication link between multiple pairs of nodes in two time slots, thereby improving the channel capacity.

  6. Irradiation studies of multimode optical fibres for use in ATLAS front-end links

    CERN Document Server

    Mahout, G; Andrieux, M L; Arvidsson, C B; Charlton, D G; Dinkespiler, B; Dowell, John D; Gallin-Martel, L; Homer, R James; Jovanovic, P; Kenyon, Ian Richard; Kuyt, G; Lundqvist, J M; Mandic, I; Martin, O; Shaylor, H R; Stroynowski, R; Troska, Jan K; Wastie, R L; Weidberg, A R; Wilson, J A; Ye, J

    2000-01-01

    The radiation tolerance of three multimode optical fibres has been investigated to establish their suitability for the use in the front- end data links of the ATLAS experiment. Both gamma and neutron irradiation studies are reported. A step-index fibre with a pure silica core showed an induced attenuation of ~0.05 dB/m at 330 kGy (Si) and 1*10/sup 15/ n(1 MeV Si)/cm/sup 2/ and is suitable for use with the inner detector links which operate at 40-80 Mb/s. A graded- index fibre with a predominantly germanium-doped core exhibits an induced attenuation of ~0.1 dB/m at 800 Gy(Si) and 2*10/sup 13/ n(1 MeV Si)/cm/sup 2/ and is suitable for the calorimeter links which operate at 1.6 Gb/s. Measurements of the dose rate dependence of the induced attenuation indicate that the attenuation in ATLAS will be lower. (30 refs).

  7. Irradiation studies of multimode optical fibres for use in ATLAS front-end links

    International Nuclear Information System (INIS)

    Mahout, G.; Pearce, M.; Andrieux, M-L.; Arvidsson, C-B.; Charlton, D.G.; Dinkespiler, B.; Dowell, J.D.; Gallin-Martel, L.; Homer, R.J.; Jovanovic, P.; Kenyon, I.R.; Kuyt, G.; Lundquist, J.; Mandic, I.; Martin, O.; Shaylor, H.R.; Stroynowski, R.; Troska, J.; Wastie, R.L.; Weidberg, A.R.; Wilson, J.A.; Ye, J.

    2000-01-01

    The radiation tolerance of three multimode optical fibres has been investigated to establish their suitability for the use in the front-end data links of the ATLAS experiment. Both gamma and neutron irradiation studies are reported. A step-index fibre with a pure silica core showed an induced attenuation of ∼0.05 dB/m at 330 kGy(Si) and 1x10 15 n(1 MeV Si)/cm 2 and is suitable for use with the inner detector links which operate at 40-80 Mb/s. A graded-index fibre with a predominantly germanium-doped core exhibits an induced attenuation of ∼0.1 dB/m at 800 Gy(Si) and 2x10 13 n(1 MeV Si)/cm 2 and is suitable for the calorimeter links which operate at 1.6 Gb/s. Measurements of the dose rate dependence of the induced attenuation indicate that the attenuation in ATLAS will be lower

  8. A Novel Dedicated Route Protection Scheme for Survivability of Link Failure in Elastic Optical Networks

    Directory of Open Access Journals (Sweden)

    Sridhar Iyer

    2017-11-01

    Full Text Available The spectrally efficient transportation of the high bit rate(s data is achievable by the Elastic optical networks (EONs. However, in the EONs, owing to the failure occurrence even in an individual simple element, different service(s maybe interrupted. Hence, it is imperative that the schemes for survivability be developed so that the issues due to the possible failure(s can be overcome. In the current work, in view of survivability of the link failure(s in the EONs, we propose the Spectrum Continuity and Contiguity Established DRP (SCC-E-DRP algorithm which is a novel dedicated route protection (DRP scheme that attempts to avoid the problem of trap topology during its exploration for a pair of link disjoint path. Further, to evaluate the link disjoint paths, we resort to the use of the SCC Established Shortest Route (SCC-E-SR algorithm which is a modified Dijkstra’s algorithm based scheme that selects the path(s pair(s based on the end-toend SCC. We conduct extensive simulations considering realistic network topologies, and compare the performance of the SCCE-DRP scheme with the existing techniques. The obtained results show that, compared to the existing schemes, the SCC-E-DRP scheme achieves better results in terms of blocking probability.

  9. Accuracy and User Performance Evaluation of a New, Wireless-enabled Blood Glucose Monitoring System That Links to a Smart Mobile Device.

    Science.gov (United States)

    Bailey, Timothy S; Wallace, Jane F; Pardo, Scott; Warchal-Windham, Mary Ellen; Harrison, Bern; Morin, Robert; Christiansen, Mark

    2017-07-01

    The new Contour ® Plus ONE blood glucose monitoring system (BGMS) features an easy-to-use, wireless-enabled blood glucose meter that links to a smart mobile device via Bluetooth ® connectivity and can sync with the Contour ™ Diabetes app on a smartphone or tablet. The accuracy of the new BGMS was assessed in 2 studies according to ISO 15197:2013 criteria. In Study 1 (laboratory study), fingertip capillary blood samples from 100 subjects were tested in duplicate using 3 test strip lots. In Study 2 (clinical study), 134 subjects with type 1 or type 2 diabetes enrolled at 2 clinical sites. BGMS results and YSI analyzer (YSI) reference results were compared for fingertip blood obtained by untrained subjects' self-testing and for study staff-obtained fingertip, subject palm, and venous results. In Study 1, 99.0% (594/600) of combined results for all 3 test strip lots fulfilled ISO 15197:2013 Section 6.3 accuracy criteria. In Study 2, 99.2% (133/134) of subject-obtained capillary fingertip results, 99.2% (133/134) of study staff-obtained fingertip results, 99.2% (125/126) of subject-obtained palm results, and 100% (132/132) of study staff-obtained venous results met ISO 15197:2013 Section 8 accuracy criteria. Moreover, 95.5% (128/134) of subject-obtained fingertip self-test results were within ±10 mg/dl (±0.6 mmol/L) or ±10% of the YSI reference result. Questionnaire results showed that most subjects found the BGMS easy to use. The BGMS exceeded ISO 15197:2013 accuracy criteria both in the laboratory and in a clinical setting when used by untrained subjects with diabetes.

  10. Effect of soil temperature on optical frequency transfer through unidirectional dense-wavelength-division-multiplexing fiber-optic links

    NARCIS (Netherlands)

    Pinkert, T.J.; Boll, O.; Willmann, L.; Jansen, G.S.M.; Dijck, E.A.; Groeneveld, B.G.H.M.; Smets, R.; Bosveld, F.C.; Ubachs, W.M.G.; Jungmann, K.; Eikema, K.S.E.; Koelemeij, J.C.J.

    2015-01-01

    Results of optical frequency transfer over a carrier-grade dense-wavelength-division-multiplexing (DWDM) optical fiber network are presented. The relation between soil temperature changes on a buried optical fiber and frequency changes of an optical carrier through the fiber is modeled. Soil

  11. Effect of soil temperature on optical frequency transfer through unidirectional dense-wavelength-divisionmultiplexing fiber-optic links

    NARCIS (Netherlands)

    Pinkert, T.J.; Böll, O.; Willmann, Lorenz; Jansen, G.S.M.; Dijck, E.A.; Groeneveld, B.G.H.M.; Smets, R.; Bosveld, F.C.; Ubachs, W.; Jungmann, K.; Eikema, K.S.E.; Koelemeij, J.C.J.

    2015-01-01

    Results of optical frequency transfer over a carrier-grade dense-wavelength-division-multiplexing (DWDM) optical fiber network are presented. The relation between soil temperature changes on a buried optical fiber and frequency changes of an optical carrier through the fiber is modeled. Soil

  12. Synchronic, optical transmission data link integrated with FPGA circuits (for TESLA LLRF control system)

    Energy Technology Data Exchange (ETDEWEB)

    Zielinski, J.S.

    2006-07-15

    The X-ray free-electron laser X-FEL that is being planned at the DESY research center in cooperation with European partners will produce high-intensity ultra-short X-ray flashes with the properties of laser light. This new light source, which can only be described in terms of superlatives, will open up a whole range of new possibilities for the natural sciences. It could also offer very promising opportunities for industrial users. SIMCON (SIMulator and CONtroller) is the project of the fast, low latency digital controller dedicated to the LLRF1 system in VUV FEL experiment It is being developed by the ELHEP2 group in the Institute of Electronic Systems at Warsaw University of Technology. The main purpose of the project is to create a controller to stabilize the vector sum of fields in cavities of one cryo-module in the experiment. The device can be also used as the simulator of the cavity and test bench for other devices. The synchronic, optical link project was made for the accelerator X-FEL laser TESLA, the LLRF control system experiment at DESY, Hamburg. The control and diagnostic data is transmitted up to 2.5Gbit/s through a plastic fiber in a distance up to a few hundred meters. The link is synchronized once after power up, and never resynchronized when data is transmitted with maximum speed. The one way link bit error rate is less then 10{sup -15}. The transceiver component written in VHDL that works in the dedicated Altera registered Stratix registered GX FPGA circuit. During the work in the PERG laboratory a 2,5Gbit/s serial link with the long vector parallel interface transceiver was created. Long-Data-Vector transceiver transmits 16bit vector each 8ns with 120ns latency. (orig.)

  13. Synchronic, optical transmission data link integrated with FPGA circuits (for TESLA LLRF control system)

    International Nuclear Information System (INIS)

    Zielinski, J.S.

    2006-05-01

    The X-ray free-electron laser X-FEL that is being planned at the DESY research center in cooperation with European partners will produce high-intensity ultra-short X-ray flashes with the properties of laser light. This new light source, which can only be described in terms of superlatives, will open up a whole range of new possibilities for the natural sciences. It could also offer very promising opportunities for industrial users. SIMCON (SIMulator and CONtroller) is the project of the fast, low latency digital controller dedicated to the LLRF1 system in VUV FEL experiment It is being developed by the ELHEP2 group in the Institute of Electronic Systems at Warsaw University of Technology. The main purpose of the project is to create a controller to stabilize the vector sum of fields in cavities of one cryo-module in the experiment. The device can be also used as the simulator of the cavity and test bench for other devices. The synchronic, optical link project was made for the accelerator X-FEL laser TESLA, the LLRF control system experiment at DESY, Hamburg. The control and diagnostic data is transmitted up to 2.5Gbit/s through a plastic fiber in a distance up to a few hundred meters. The link is synchronized once after power up, and never resynchronized when data is transmitted with maximum speed. The one way link bit error rate is less then 10 -15 . The transceiver component written in VHDL that works in the dedicated Altera registered Stratix registered GX FPGA circuit. During the work in the PERG laboratory a 2,5Gbit/s serial link with the long vector parallel interface transceiver was created. Long-Data-Vector transceiver transmits 16bit vector each 8ns with 120ns latency. (orig.)

  14. Wireless Internet

    NARCIS (Netherlands)

    el Zarki, M.; Heijenk, Geert; Lee, Kenneth S.; Bidgoli, H.

    This chapter addresses the topic of wireless Internet, the extension of the wireline Internet architecture to the wireless domain. As such the chapter introduces the reader to the dominant characteristics of the Internet, from its structure to the protocols that control the forwarding of data and

  15. On nonlinearly-induced noise in single-channel optical links with digital backpropagation.

    Science.gov (United States)

    Beygi, Lotfollah; Irukulapati, Naga V; Agrell, Erik; Johannisson, Pontus; Karlsson, Magnus; Wymeersch, Henk; Serena, Paolo; Bononi, Alberto

    2013-11-04

    In this paper, we investigate the performance limits of electronic chromatic dispersion compensation (EDC) and digital backpropagation (DBP) for a single-channel non-dispersion-managed fiber-optical link. A known analytical method to derive the performance of the system with EDC is extended to derive a first-order approximation for the performance of the system with DBP. In contrast to the cubic growth of the variance of the nonlinear noise-like interference, often called nonlinear noise, with input power for EDC, a quadratic growth is observed with DBP using this approximation. Finally, we provide numerical results to verify the accuracy of the proposed approach and compare it with existing analytical models.

  16. Mach-Zehnder fiber-optic links for reaction history measurements at the National Ignition Facility

    International Nuclear Information System (INIS)

    Miller, E Kirk; Herrmann, H W; Stoeffl, W; Horsfield, C J

    2010-01-01

    We present the details of the analog fiber-optic data link that will be used in the chamber-mounted Gamma Reaction History (GRH) diagnostic at the National Ignition Facility (NIF) located at the Lawrence Livermore Laboratory in Livermore, California. The system is based on Mach-Zehnder (MZ) modulators integrated into the diagnostic, with the source lasers and bias control electronics located remotely to protect the active electronics. A complete recording system for a single GRH channel comprises two MZ modulators, with the fiber signals split onto four channels on a single digitizer. By carefully selecting the attenuation, the photoreceiver, and the digitizer settings, the dynamic range achievable is greater than 1000:1 at the full system bandwidth of greater than 10 GHz. The system is designed to minimize electrical reflections and mitigate the effects of transient radiation darkening on the fibers.

  17. Introduction to wireless sensor networks

    CERN Document Server

    Forster, Anna

    2016-01-01

    Explores real-world wireless sensor network development, deployment, and applications. The book begins with an introduction to wireless sensor networks and their fundamental concepts. Hardware components, operating systems, protocols, and algorithms that make up the anatomy of a sensor node are described in chapter two. Properties of wireless communications, medium access protocols, wireless links, and link estimation protocols are described in chapter three and chapter four. Routing basics and metrics, clustering techniques, time synchronization and localization protocols, as well as sensing techniques are introduced in chapter five to nine. The concluding chapter summarizes the learnt methods and shows how to use them to deploy real-world sensor networks in a structured way.

  18. System performances of optical space code-division multiple-access-based fiber-optic two-dimensional parallel data link.

    Science.gov (United States)

    Nakamura, M; Kitayama, K

    1998-05-10

    Optical space code-division multiple access is a scheme to multiplex and link data between two-dimensional processors such as smart pixels and spatial light modulators or arrays of optical sources like vertical-cavity surface-emitting lasers. We examine the multiplexing characteristics of optical space code-division multiple access by using optical orthogonal signature patterns. The probability density function of interference noise in interfering optical orthogonal signature patterns is calculated. The bit-error rate is derived from the result and plotted as a function of receiver threshold, code length, code weight, and number of users. Furthermore, we propose a prethresholding method to suppress the interference noise, and we experimentally verify that the method works effectively in improving system performance.

  19. Suppression of optical beat interference-noise in orthogonal frequency division multiple access-passive optical network link using self-homodyne balanced detection

    Science.gov (United States)

    Won, Yong-Yuk; Jung, Sang-Min; Han, Sang-Kook

    2014-08-01

    A new technique, which reduces optical beat interference (OBI) noise in orthogonal frequency division multiple access-passive optical network (OFDMA-PON) links, is proposed. A self-homodyne balanced detection, which uses a single laser for the optical line terminal (OLT) as well as for the optical network unit (ONU), reduces OBI noise and also improves the signal to noise ratio (SNR) of the discrete multi-tone (DMT) signal. The proposed scheme is verified by transmitting quadrature phase shift keying (QPSK)-modulated DMT signal over a 20-km single mode fiber. The optical signal to noise ratio (OSNR), that is required for BER of 10-5, is reduced by 2 dB in the balanced detection compared with a single channel due to the cancellation of OBI noise in conjunction with the local laser.

  20. Physical-layer security analysis of PSK quantum-noise randomized cipher in optically amplified links

    Science.gov (United States)

    Jiao, Haisong; Pu, Tao; Xiang, Peng; Zheng, Jilin; Fang, Tao; Zhu, Huatao

    2017-08-01

    The quantitative security of quantum-noise randomized cipher (QNRC) in optically amplified links is analyzed from the perspective of physical-layer advantage. Establishing the wire-tap channel models for both key and data, we derive the general expressions of secrecy capacities for the key against ciphertext-only attack and known-plaintext attack, and that for the data, which serve as the basic performance metrics. Further, the maximal achievable secrecy rate of the system is proposed, under which secrecy of both the key and data is guaranteed. Based on the same framework, the secrecy capacities of various cases can be assessed and compared. The results indicate perfect secrecy is potentially achievable for data transmission, and an elementary principle of setting proper number of photons and bases is given to ensure the maximal data secrecy capacity. But the key security is asymptotically perfect, which tends to be the main constraint of systemic maximal secrecy rate. Moreover, by adopting cascaded optical amplification, QNRC can realize long-haul transmission with secure rate up to Gb/s, which is orders of magnitude higher than the perfect secrecy rates of other encryption systems.