WorldWideScience

Sample records for radio communication system

  1. Intelligent Wireless Communication System Using Cognitive Radio

    Directory of Open Access Journals (Sweden)

    Asma Amraoui

    2012-04-01

    Full Text Available The increasing demand for wireless communication introduces efficient spectrum utilization challenge. To address this challenge, cognitive radio (CR is emerged as the key technology; which enables opportunistic access to the spectrum. CR is a form of wireless communication in which a transceiver can intelligently detect which communication channels are in use and which are not, and instantly move into vacant channels while avoiding occupied ones. This optimizes the use of available radio-frequency (RFspectrum while minimizing interference to other users. In this paper, we present a state of the art onthe use of Multi Agent Systems (MAS for spectrum access using cooperation and competition to solve the problem of spectrum allocation and ensure better management. Then we propose a new approach which uses the CR for improving wireless communication for a single cognitive radio mobile terminal (CRMT.

  2. Integrated Train Ground Radio Communication System Based TD-LTE

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hongli; CAO Yuan; ZHU Li; XU Wei

    2016-01-01

    In existing metro systems, the train ground radio communication system for different applications are deployed independently. Investing and constructing the communication infrastructures repeatedly wastes substan-tial social resources, and it brings difficulties to maintain all these infrastructures. We present the communication Quality of service (QoS) requirement for different train ground radio applications. An integrated TD-LTE based train ground radio communication system for the metro system (LTE-M) is designed next. In order to test the LTE-M system performance, an indoor testing environment is set up. The channel simulator and programmable attenua-tors are used to simulate the real metro environment. Ex-tensive test results show that the designed LTE-M system performance satisfies metro communication requirements.

  3. Radio propagation for space communications systems

    Science.gov (United States)

    Ippolito, L. J.

    1981-01-01

    This paper presents a review of the most recent information on the effects of the earth's atmosphere on space communications systems. Models and techniques used in the prediction of atmospheric effects as influenced by frequency, geography, elevation angle, and type of transmission are discussed. Recent data on performance characteristics obtained from direct measurements on satellite links operating to above 30 GHz are reviewed. Particular emphasis is placed on the effects of precipitation on the earth-space path, including rain attenuation, and rain and ice-particle depolarization. Sky noise, antenna gain degradation, scintillations, and bandwidth coherence are also discussed. The impact of the various propagation factors on communications system design criteria is presented. These criteria include link reliability, power margins, noise contributions, modulation and polarization factors, channel crosstalk, error-rate, and bandwidth limitations.

  4. Tunnel radio communications system at Stanford Linear Accelerator Center

    Energy Technology Data Exchange (ETDEWEB)

    Struven, W.C.

    1980-07-01

    A unique single frequency, dual daisy chain tunnel radio communication system has been developed for use in our new Positron-Electron Storage Ring. Communications are possible between portables in the underground ring and between a portable in the ring and all control rooms on the site. The system is designed as a wide band facility and therefore can carry many simplex and duplex transmissions. This system utilizes TV twinlead as a distributed antenna and repeater amplifiers to cover more than 7000 feet of underground tunnel. The design philosophy, tests and initial design are discussed and contrasted with the final implementation of the system. Future uses of the system are discussed.

  5. Technology Evaluation of Programmable Communicating Thermostats with Radio Broadcast Data System Communications

    Energy Technology Data Exchange (ETDEWEB)

    Herter, Karen; Wayland, Seth

    2008-10-31

    Programmable Communicating Thermostats are thermostats that can be programmed by the user to respond to signals indicating a grid-level system emergency or pricing event. The California Energy Commission is considering standards that would include a requirement for Programmable Communicating Thermostats in residential and small commercial applications. The current specification for Programmable Communicating Thermostats requires Radio Data System communications to Programmable Communicating Thermostats. This study tested the signal strength and reliability of Radio Data System signals at 40 customer sites within the Sacramento Municipal Utility District, which is serviced by 17 radio stations that already transmit Radio Data System signals. The study also tested the functionality of a commercially available Programmable Communicating Thermostat for compliance with California Energy Commission design standards. Test results demonstrated that Radio Data System is capable of reliably sending price and emergency signals. This study also provides evidence that existing Programmable Communicating Thermostats, on receiving a Radio Data System pricing or event signal, are capable of automatically increasing set points to a customer-determined or utility-determined level, thus providing air-conditioning demand response within seconds or just a few (less than 5) minutes.

  6. A Radio Communication System for Neuronal Signals

    Institute of Scientific and Technical Information of China (English)

    Wang Min; Yang Maoquan; Wang Xiaojun; Guang Kui; Zhang Xiao

    2012-01-01

    To collect neuronal activity data from awake, freely behaving animals, we developed miniature telemetry recording system. The integrated system consists of four major components: l) Microelectrodes and micro-driver assembly, 2) analog front end (AFE), 3) programmable system on chip (PSoC), and 4) ra- dio transceiver and the LabVIEW were used as a platform for the graphic user interface. The result showed the system was able to record and analyze neuronal recordings in freely moving animals and lasted continuously for a time period of a week or more. This is very useful for the study of the interdisciplinary research of neu- roscience and information engineering techniques. The circuits and architecture of the devices can be adapted for neurobiology and research with other small animals.

  7. 77 FR 28797 - Redundancy of Communications Systems: Backup Power Private Land Mobile Radio Services: Selection...

    Science.gov (United States)

    2012-05-16

    ..., Communications common carriers, Communications equipment, Radio, Telecommunications, Telephone, Television... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 12 and 90 Redundancy of Communications Systems: Backup Power Private Land...

  8. Experimental Characterization of Extremely Broadband THz Impulse Radio Communication Systems

    DEFF Research Database (Denmark)

    Yu, Xianbin; Vidal, Borja; Galili, Michael

    2015-01-01

    We experimentally characterize a ultrabroadband terahertz (THz) impulse radio system with up to 10 GHz repetition rate. THz generation and radiation are realized in an antenna-integrated uni-traveling-carrier photodiode (UTC-PD), and THz reception is implemented based on photoconductive sampling...... by using a photoconductive antenna (PCA). We analyze the performance in terms of bandwidth and the features of the THz pulses. A 15 dB bandwidth of 1 THz confirms that this THz impulse system has a great potential of supporting ultrafast data rates, eventually for Terabit wireless communication era....

  9. An Optical Receiver Post-Processing System for the Integrated Radio and Optical Communications Software Defined Radio Test Bed

    Science.gov (United States)

    Nappier, Jennifer M.; Tokars, Roger P.; Wroblewski, Adam C.

    2016-01-01

    The Integrated Radio and Optical Communications (iROC) project at the National Aeronautics and Space Administration's (NASA) Glenn Research Center is investigating the feasibility of a hybrid radio frequency (RF) and optical communication system for future deep space missions. As a part of this investigation, a test bed for a radio frequency (RF) and optical software defined radio (SDR) has been built. Receivers and modems for the NASA deep space optical waveform are not commercially available so a custom ground optical receiver system has been built. This paper documents the ground optical receiver, which is used in order to test the RF and optical SDR in a free space optical communications link.

  10. Ionosphere and Radio Communication

    Indian Academy of Sciences (India)

    Saradi Bora

    2017-02-01

    The Earth's ionosphere consists of plasma produced by thephotoionization of thin upper atmospheric gases by UV raysand photons of short wavelength from the sun. The upperionosphere is used for radio communication and navigationas it reflects long, medium, as well as short radio waves. Sincesolar radiation is the main cause of the existence of ionosphere,any variation in the radiations can affect the entireradio communication system. This article attempts to brieflyintroduce the readers to the study of ionosphere in the contextof its use as a radio reflector, with particular reference toIndia.

  11. FQPSK techniques for satellite and mobile radio communications systems

    Science.gov (United States)

    Li, Yazhuo; Tang, Jing; Tao, Xiaofeng

    2005-11-01

    A continuous phase modulation (CPM) and constant envelope modulation (CEM) alternative of Feher-Patented quadrature phase-shift keying (FQPSK) modulation technique is presented. It is found to provide good spectral efficiencies, power efficiencies, and bit error rate (BER) performance. The modulation schemes of FQPSK are described. The spectral efficiencies, BER performance are also compared with FQPSK and other modulation techniques which are widely used in current mobile and cordless radio standards. The results show that FQPSK modulated signal exhibits much less spectrum spreading than QPSK, OQPSK, and MSK, and the error probability performance of the FQPSK is superior to those in narrow-band nonlinear channels. Based on that, the system capacity and power dissipation are also analyzed for communication systems. It is found that the encoder or receiver for the FQPSK signal to be fully compatible with original I/Q modulated one. FQPSK technique is suitable for nonlinear channels, such as satellite and mobile communications systems reducing the AM/AM and AM/PM adverse effects. At last it is also attempted to extend the application in 3G (CDMA) and 4G (OFDM) mobile communications systems.

  12. Radio-wave propagation for space communications systems

    Science.gov (United States)

    Ippolito, L. J.

    1981-01-01

    The most recent information on the effects of Earth's atmosphere on space communications systems is reviewed. The design and reliable operation of satellite systems that provide the many applications in space which rely on the transmission of radio waves for communications and scientific purposes are dependent on the propagation characteristics of the transmission path. The presence of atmospheric gases, clouds, fog, precipitation, and turbulence causes uncontrolled variations in the signal characteristics. These variations can result in a reduction of the quality and reliability of the transmitted information. Models and other techniques are used in the prediction of atmospheric effects as influenced by frequency, geography, elevation angle, and type of transmission. Recent data on performance characteristics obtained from direct measurements on satellite links operating to above 30 GHz have been reviewed. Particular emphasis has been placed on the effects of precipitation on the Earth/space path, including rain attenuation, and ice particle depolarization. Other factors are sky noise, antenna gain degradation, scintillations, and bandwidth coherence. Each of the various propagation factors has an effect on design criteria for communications systems. These criteria include link reliability, power margins, noise contribution, modulation and polarization factors, channel cross talk, error rate, and bandwidth limitations.

  13. Electromagnetic compatibility fundamentals applied to spacecraft radio communication systems

    Science.gov (United States)

    Haber, F.; Celebiler, M.; Weil-Malherbe, C.

    1971-01-01

    A design guide for minimizing electromagnetic interference in aerospace communication equipment for ground stations is presented. Specifically treated are the mechanisms of generating unwanted radio emissions that may affect station operations as well as other communications services, the mechanisms by which sensitive receivers become susceptible to interference, means for reducing interference, standard methods of measurement, and the problems of site selection. The sources of interference are viewed primarily as originating from communications transmitters aboard spacecraft and aircraft, ground transmitters within and outside the ground stations, and other electrical sources on the ground that are not intended to radiate.

  14. Commercial Radio as Communication.

    Science.gov (United States)

    Rothenbuhler, Eric W.

    1996-01-01

    Compares the day-to-day work routines of commercial radio with the principles of a theoretical communication model. Illuminates peculiarities of the conduct of communication by commercial radio. Discusses the application of theoretical models to the evaluation of practicing institutions. Offers assessments of commercial radio deriving from…

  15. A low-power photovoltaic system with energy storage for radio communications: Description and design methodology

    Science.gov (United States)

    Chapman, C. P.; Chapman, P. D.; Lewison, A. H.

    1982-01-01

    A low power photovoltaic system was constructed with approximately 500 amp hours of battery energy storage to provide power to an emergency amateur radio communications center. The system can power the communications center for about 72 hours of continuous nonsun operation. Complete construction details and a design methodology algorithm are given with abundant engineering data and adequate theory to allow similar systems to be constructed, scaled up or down, with minimum design effort.

  16. Albanian: Basic Radio Communications.

    Science.gov (United States)

    Defense Language Inst., Washington, DC.

    This volume has been designed as a supplement to a course in Albanian developed by the Defense Language Institute. The emphasis in this text is placed on radio communications instruction. The volume is divided into five exercises, each of which contains a vocabulary, dictation, and an air-to-ground communications procedure conducted in Albanian…

  17. A New Signaling Architecture THREP with Autonomous Radio-Link Control for Wireless Communications Systems

    Science.gov (United States)

    Hirono, Masahiko; Nojima, Toshio

    This paper presents a new signaling architecture for radio-access control in wireless communications systems. Called THREP (for THREe-phase link set-up Process), it enables systems with low-cost configurations to provide tetherless access and wide-ranging mobility by using autonomous radio-link controls for fast cell searching and distributed call management. A signaling architecture generally consists of a radio-access part and a service-entity-access part. In THREP, the latter part is divided into two steps: preparing a communication channel, and sustaining it. Access control in THREP is thus composed of three separated parts, or protocol phases. The specifications of each phase are determined independently according to system requirements. In the proposed architecture, the first phase uses autonomous radio-link control because we want to construct low-power indoor wireless communications systems. Evaluation of channel usage efficiency and hand-over loss probability in the personal handy-phone system (PHS) shows that THREP makes the radio-access sub-system operations in a practical application model highly efficient, and the results of a field experiment show that THREP provides sufficient protection against severe fast CNR degradation in practical indoor propagation environments.

  18. Radio resource management for next generation mobile communication systems

    DEFF Research Database (Denmark)

    Wang, Hua

    technological novelties. Those technological breaks impose significant challenges on the design of advanced and completely new Radio Resource Management (RRM) algorithms, such as channel assignments and packet scheduling. Among the emerging technologies for broadband wireless access, special attention has been...... paid on IEEE 802.16 based technology, also known as WiMAX, for its capability to support high transmission rates and diverse QoS requirements. The objective of this Ph.D. thesis has two-fold: to design advanced RRM algorithms with different QoS support in single-hop 802.16j relay network, from physical...

  19. Numerical arc segmentation algorithm for a radio conference - A software tool for communication satellite systems planning

    Science.gov (United States)

    Whyte, W. A.; Heyward, A. O.; Ponchak, D. S.; Spence, R. L.; Zuzek, J. E.

    1988-01-01

    A detailed description of a Numerical Arc Segmentation Algorithm for a Radio Conference (NASARC) software package for communication satellite systems planning is presented. This software provides a method of generating predetermined arc segments for use in the development of an allotment planning procedure to be carried out at the 1988 World Administrative Radio Conference (WARC - 88) on the use of the GEO and the planning of space services utilizing GEO. The features of the NASARC software package are described, and detailed information is given about the function of each of the four NASARC program modules. The results of a sample world scenario are presented and discussed.

  20. Space Telecommunications Radio System STRS Cognitive Radio

    Science.gov (United States)

    Briones, Janette C.; Handler, Louis M.

    2013-01-01

    Radios today are evolving from awareness toward cognition. A software defined radio (SDR) provides the most capability for integrating autonomic decision making ability and allows the incremental evolution toward a cognitive radio. This cognitive radio technology will impact NASA space communications in areas such as spectrum utilization, interoperability, network operations, and radio resource management over a wide range of operating conditions. NASAs cognitive radio will build upon the infrastructure being developed by Space Telecommunication Radio System (STRS) SDR technology. This paper explores the feasibility of inserting cognitive capabilities in the NASA STRS architecture and the interfaces between the cognitive engine and the STRS radio. The STRS architecture defines methods that can inform the cognitive engine about the radio environment so that the cognitive engine can learn autonomously from experience, and take appropriate actions to adapt the radio operating characteristics and optimize performance.

  1. Development of data communication system with ultra high frequency radio wave for implantable artificial hearts.

    Science.gov (United States)

    Tsujimura, Shinichi; Yamagishi, Hiroto; Sankai, Yoshiyuki

    2009-01-01

    In order to minimize infection risks of patients with artificial hearts, wireless data transmission methods with electromagnetic induction or light have been developed. However, these methods tend to become difficult to transmit data if the external data transmission unit moves from its proper position. To resolve this serious problem, the purpose of this study is to develop a prototype wireless data communication system with ultra high frequency radio wave and confirm its performance. Due to its high-speed communication rate, low power consumption, high tolerance to electromagnetic disturbances, and secure wireless communication, we adopted Bluetooth radio wave technology for our system. The system consists of an internal data transmission unit and an external data transmission unit (53 by 64 by 16 mm, each), and each has a Bluetooth module (radio field intensity: 4 dBm, receiver sensitivity: -80 dBm). The internal unit also has a micro controller with an 8-channel 10-bit A/D converter, and the external unit also has a RS-232C converter. We experimented with the internal unit implanted into pig meat, and carried out data transmission tests to evaluate the performance of this system in tissue thickness of up to 3 mm. As a result, data transfer speeds of about 20 kbps were achieved within the communication distance of 10 m. In conclusion, we confirmed that the system can wirelessly transmit the data from the inside of the body to the outside, and it promises to resolve unstable data transmission due to accidental movements of an external data transmission unit.

  2. Characterization of Impulse Radio Intrabody Communication System for Wireless Body Area Networks.

    Science.gov (United States)

    Cai, Zibo; Seyedi, MirHojjat; Zhang, Weiwei; Rivet, Francois; Lai, Daniel T H

    2017-01-01

    Intrabody communication (IBC) is a promising data communication technique for body area networks. This short-distance communication approach uses human body tissue as the medium of signal propagation. IBC is defined as one of the physical layers for the new IEEE 802.15.6 or wireless body area network (WBAN) standard, which can provide a suitable data rate for real-time physiological data communication while consuming lower power compared to that of radio-frequency protocols such as Bluetooth. In this paper, impulse radio (IR) IBC (IR-IBC) is examined using a field-programmable gate array (FPGA) implementation of an IBC system. A carrier-free pulse position modulation (PPM) scheme is implemented using an IBC transmitter in an FPGA board. PPM is a modulation technique that uses time-based pulse characteristics to encode data based on IR concepts. The transmission performance of the scheme was evaluated through signal propagation measurements of the human arm using 4- and 8-PPM transmitters, respectively. 4 or 8 is the number of symbols during modulations. It was found that the received signal-to-noise ratio (SNR) decreases approximately 8.0 dB for a range of arm distances (5-50 cm) between the transmitter and receiver electrodes with constant noise power and various signal amplitudes. The SNR for the 4-PPM scheme is approximately 2 dB higher than that for the 8-PPM one. In addition, the bit error rate (BER) is theoretically analyzed for the human body channel with additive white Gaussian noise. The 4- and 8-PPM IBC systems have average BER values of 10(-5) and 10(-10), respectively. The results indicate the superiority of the 8-PPM scheme compared to the 4-PPM one when implementing the IBC system. The performance evaluation of the proposed IBC system will improve further IBC transceiver design.

  3. Software Defined Electronics: A Revolutionary Change in Design and Teaching Paradigm of RF Radio Communications Systems

    Directory of Open Access Journals (Sweden)

    Géza Kolumbán

    2015-06-01

    Full Text Available Band-pass signals are used everywhere in radio communications. The band-pass property makes the substitution of each RF/microwave/ optical analog signal processing possible with a low-frequency digital one in Software Defined Electronics (SDE. In SDE, the high frequency band-pass signals are transformed into the BaseBand (BB by a universal HW device and every application is implemented in BB, entirely in software. SDE concept uses (i the lowest sampling rate attainable theoretically and (ii the same universal HW device in every application. The huge level of flexibility offered by the SW implementation is essential in many applications from cognitive radio to adaptive reconfigurable systems. This tutorial, written for interested readers who have no solid background in software defined radio, virtual instrumentation and SoC technology, surveys the SDE theory, uses a step-by-step approach for the derivation of BB equivalents and demonstrates the application of SDE concept in scientific research, prototyping and education.

  4. Experimental evaluation of a radio-on-FSO communication system for multiple RF signal transmission

    Science.gov (United States)

    Kazaura, Kamugisha; Dat, Pham; Bekkali, Abdelmoula; Shah, Alam; Suzuki, Toshiji; Wakamori, Kazuhiko; Matsumoto, Mitsuji; Nakamura, Takuya; Takahashi, Koichi; Higashino, Takeshi; Aburakawa, Yuji; Tsukamoto, Katsutoshi; Komaki, Shozo

    2009-02-01

    In this paper we present the design concept plus experimental results and evaluation of a newly developed advanced DWDM Radio-on-Free-Space Optical (RoFSO) communication system capable of simultaneous transmission of multiple RF signals. The RoFSO system is evaluated based on the performance metric parameters defined for the various RF signals comprising of different wireless services including terrestrial digital broadcasting signals, cellular 3GPP W-CDMA signals, IEEE 802.11 WLAN based signals etc being transmitted over the RoFSO link. The performance metric parameters being considered include standard optical received power, CNR and BER characteristics, W-CDMA signal transmission metric parameters like Adjacent Channel Leakage Ratio (ACLR) and Error Vector Magnitude (EVM), modulation error ratio (MER) for digital terrestrial television broadcasting signals as well as spectrum mask and EVM for IEEE 802.11 Wireless LAN signal transmission.

  5. Radio Frequency Identification (RFID) and communication technologies for solid waste bin and truck monitoring system.

    Science.gov (United States)

    Hannan, M A; Arebey, Maher; Begum, R A; Basri, Hassan

    2011-12-01

    This paper deals with a system of integration of Radio Frequency Identification (RFID) and communication technologies for solid waste bin and truck monitoring system. RFID, GPS, GPRS and GIS along with camera technologies have been integrated and developed the bin and truck intelligent monitoring system. A new kind of integrated theoretical framework, hardware architecture and interface algorithm has been introduced between the technologies for the successful implementation of the proposed system. In this system, bin and truck database have been developed such a way that the information of bin and truck ID, date and time of waste collection, bin status, amount of waste and bin and truck GPS coordinates etc. are complied and stored for monitoring and management activities. The results showed that the real-time image processing, histogram analysis, waste estimation and other bin information have been displayed in the GUI of the monitoring system. The real-time test and experimental results showed that the performance of the developed system was stable and satisfied the monitoring system with high practicability and validity.

  6. Spectrum management and radio resource management considering cognitive radio systems

    NARCIS (Netherlands)

    Haartsen, Jaap C.; Wieweg, Lasse; Huschke, Jörg

    2005-01-01

    International fora and some national administrations define a cognitive radio (CR) as a pioneering radio communication system that would be capable of altering and adapting its transmitter and receiver parameters based on communication and the exchange of information with related detectable radio co

  7. Comparative Study of Optical and Radio-Frequency Communication Systems for a Deep-Space Mission

    Science.gov (United States)

    Hemmati, H.; Wilson, K.; Sue, M. K.; Harcke, L. J.; Wilhelm, M.; Chen, C.-C.; Lesh, J.; Feria, Y.; Rascoe, D.; Lansing, F.

    1997-01-01

    We have performed a study on telecommunication systems for a hypothetical mission to Mars. The objective of the study was to evaluate and compare the benefits that microwave-X-band (8.4 GHz) and Ka-band (32 GHz) - and optical communications technologies a afford to future missions. The telecommunication systems were required to return data after launch and in orbit at 2.7 AU with daily data volumes of 0.1, 1.0, or 10.0 Gbits (Gb). Spacecraft terminals capable of delivering each of the three data volumes were proposed and characterized in terms of mass, power consumption, size, and cost. The estimated parameters for X-band, Ka-band, and optical frequencies are compared and presented here. For all cases, the optical light terminal exhibits about 60 percent of the mass of the corresponding radio frequency (RF) subsystem. Power consumption is comparable for all three technologies at a 0.1 Gb/day data volume, but the power required at either Ka-band or optical is less than half of the X-band requirement at 10 Gb/day. These benefits can be obtained only with a suitable investment in reception facilities for Ka-band or optical frequencies.

  8. Cryogenically cooled low-noise amplifier for radio-astronomical observations and centimeter-wave deep-space communications systems

    Science.gov (United States)

    Vdovin, V. F.; Grachev, V. G.; Dryagin, S. Yu.; Eliseev, A. I.; Kamaletdinov, R. K.; Korotaev, D. V.; Lesnov, I. V.; Mansfeld, M. A.; Pevzner, E. L.; Perminov, V. G.; Pilipenko, A. M.; Sapozhnikov, B. D.; Saurin, V. P.

    2016-01-01

    We report a design solution for a highly reliable, low-noise and extremely efficient cryogenically cooled transmit/receive unit for a large antenna system meant for radio-astronomical observations and deep-space communications in the X band. We describe our design solution and the results of a series of laboratory and antenna tests carried out in order to investigate the properties of the cryogenically cooled low-noise amplifier developed. The transmit/receive unit designed for deep-space communications (Mars missions, radio observatories located at Lagrangian point L2, etc.) was used in practice for communication with live satellites including "Radioastron" observatory, which moves in a highly elliptical orbit.

  9. Energy Efficiency in MIMO Underlay and Overlay Device-to-Device Communications and Cognitive Radio Systems

    Science.gov (United States)

    Zappone, Alessio; Matthiesen, Bho; Jorswieck, Eduard Axel

    2017-02-01

    This paper addresses the problem of resource allocation for systems in which a primary and a secondary link share the available spectrum by an underlay or overlay approach. After observing that such a scenario models both cognitive radio and D2D communications, we formulate the problem as the maximization of the secondary energy efficiency subject to a minimum rate requirement for the primary user. This leads to challenging non-convex, fractional problems. In the underlay scenario, we obtain the global solution by means of a suitable reformulation. In the overlay scenario, two algorithms are proposed. The first one yields a resource allocation fulfilling the first-order optimality conditions of the resource allocation problem, by solving a sequence of easier fractional problems. The second one enjoys a weaker optimality claim, but an even lower computational complexity. Numerical results demonstrate the merits of the proposed algorithms both in terms of energy-efficient performance and complexity, also showing that the two proposed algorithms for the overlay scenario perform very similarly, despite the different complexity.

  10. Software-Defined Radio for Space-to-Space Communications

    Science.gov (United States)

    Fisher, Ken; Jih, Cindy; Moore, Michael S.; Price, Jeremy C.; Abbott, Ben A.; Fritz, Justin A.

    2011-01-01

    A paper describes the Space- to-Space Communications System (SSCS) Software- Defined Radio (SDR) research project to determine the most appropriate method for creating flexible and reconfigurable radios to implement wireless communications channels for space vehicles so that fewer radios are required, and commonality in hardware and software architecture can be leveraged for future missions. The ability to reconfigure the SDR through software enables one radio platform to be reconfigured to interoperate with many different waveforms. This means a reduction in the number of physical radio platforms necessary to support a space mission s communication requirements, thus decreasing the total size, weight, and power needed for a mission.

  11. Voice communications over packet radio networks

    Science.gov (United States)

    Seah, M. M.

    1985-03-01

    The use of packet virtual circuit technique for voice communications in military radio networks was investigated. The work was concerned with various aspects of networking which include network modeling, communications techniques, traffic analysis and network control. An attempt has been made to develop a simple yet efficient time slot assignment algorithm . This was analyzed under a variety of slot depths and networks topologies using computer simulation. The Erlang' B results were used to provide more insight into the channel characteristics of the packet radio networks. The capabilities of implementing TDMA/CDMA hybrid schemes in the system were scrutinized. A method to estimate the transmission capacity of the inter-node links was found. We demonstrate its effectiveness in controlling local congestion by computer simulation. Graphical results were presented to highlight the behavior of the proposed packet radio networks. We concluded that an appropriate link weight function would provide efficient and reliable network services.

  12. United States Army Land Mobile Radio Communication System: Impacts of Information Assurance on Commercial Off-the-Shelf Systems

    Science.gov (United States)

    2010-06-01

    Manager; Program Manager PSTN Public Switched Telephone Network RF Radio Frequency SME Subject Matter Expert SBU Sensitive But Unclassified TDMA...Non-tactical LMRs likely to be used for communicating Sensitive But Unclassified ( SBU ) information shall meet medium or basic robustness…50

  13. Regulation of Wire and Radio Communication.

    Science.gov (United States)

    Federal Communications Commission, Washington, DC.

    This bulletin reviews early federal regulation of telegraphy, telephone, and radio communications, and the development of the Radio Acts of 1912 and 1927, the Communications Act of 1934, and the Communications Satellite Act of 1962. A large portion of the discussion focuses on the regulatory power and procedures of the Federal Communications…

  14. Localized radio frequency communication using asynchronous transfer mode protocol

    Science.gov (United States)

    Witzke, Edward L.; Robertson, Perry J.; Pierson, Lyndon G.

    2007-08-14

    A localized wireless communication system for communication between a plurality of circuit boards, and between electronic components on the circuit boards. Transceivers are located on each circuit board and electronic component. The transceivers communicate with one another over spread spectrum radio frequencies. An asynchronous transfer mode protocol controls communication flow with asynchronous transfer mode switches located on the circuit boards.

  15. Simultaneous wireless information and power transfer for spectrum sharing in cognitive radio communication systems

    KAUST Repository

    Benkhelifa, Fatma

    2016-07-26

    In this paper, we consider the simultaneous wireless information and power transfer for the spectrum sharing (SS) in cognitive radio (CR) systems with a multi-antenna energy harvesting (EH) primary receiver (PR). The PR uses the antenna switching (AS) technique that assigns a subset of the PR\\'s antennas to harvest the energy from the radio frequency (RF) signals sent by the secondary transmitter (ST), and assigns the rest of the PR\\'s antennas to decode the information data. In this context, the primary network allows the secondary network to use the spectrum as long as the interference induced by the secondary transmitter (ST)\\'s signals is beneficial for the energy harvesting process at the PR side. The objective of this work is to show that the spectrum sharing is beneficial for both the SR and PR sides and leads to a win-win situation. To illustrate the incentive of the spectrum sharing cognitive system, we evaluate the mutual outage probability (MOP) introduced in [1] which declares an outage event if the PR or the secondary receiver (SR) is in an outage. Through the simulation results, we show that the performance of our system in terms of the MOP is always better than the performance of the system in the absence of ST and improves as the ST-PR interference increases. © 2016 IEEE.

  16. Software-Defined Radio Global System for Mobile Communications Transmitter Development for Heterogeneous Network Vulnerability Testing

    Science.gov (United States)

    2013-12-01

    48  3.  Results .................................................................................................48  a.  GNU Radio ...56  b.  GNU Radio Collection...by GNU Radio of the baseband signal created by the GSM transmitter code mimicking the GSM BTS BCH prior to USRP transmission. The blue signal shows

  17. Numerical arc segmentation algorithm for a radio conference: A software tool for communication satellite systems planning

    Science.gov (United States)

    Whyte, W. A.; Heyward, A. O.; Ponchak, D. S.; Spence, R. L.; Zuzek, J. E.

    1988-01-01

    The Numerical Arc Segmentation Algorithm for a Radio Conference (NASARC) provides a method of generating predetermined arc segments for use in the development of an allotment planning procedure to be carried out at the 1988 World Administrative Radio Conference (WARC) on the Use of the Geostationary Satellite Orbit and the Planning of Space Services Utilizing It. Through careful selection of the predetermined arc (PDA) for each administration, flexibility can be increased in terms of choice of system technical characteristics and specific orbit location while reducing the need for coordination among administrations. The NASARC software determines pairwise compatibility between all possible service areas at discrete arc locations. NASARC then exhaustively enumerates groups of administrations whose satellites can be closely located in orbit, and finds the arc segment over which each such compatible group exists. From the set of all possible compatible groupings, groups and their associated arc segments are selected using a heuristic procedure such that a PDA is identified for each administration. Various aspects of the NASARC concept and how the software accomplishes specific features of allotment planning are discussed.

  18. A Novel Pulse Shaping for UWB Impulse Radio IEEE 802.15.4a Communications Systems

    Directory of Open Access Journals (Sweden)

    BARRAJ Imen

    2014-05-01

    Full Text Available This paper presents a novel pulse shape which we call modified triangular pulse (MTri for Impulse Radio-Ultra Wide Band (IR-UWB IEEE 802.15.4a systems. The MTri pulse and UWB shapes previously proposed for low power IR-UWB transceivers topologies are studied and compared. The performance measures considered are compliance with required spectral emission constrains, Mask Loss (ML power and pulse energy. Our theoretical and simulations results show the advantages of the MTri pulse over studies UWB pulses. It presents the lower ML power about 0.45dB and the higher pulse energy of 0.45nJ/p.

  19. Socio-Economic Aspects of National Communication Systems: III. Radio Broadcasting in Venezuela. Communication and Society, 12.

    Science.gov (United States)

    Capriles, Oswaldo; And Others

    The third in a series that examines the role of radio broadcasting in the process of socioeconomic and cultural change in three countries with different types of broadcasting organization--Austria, Czechoslovakia, and Venezuela--this volume focuses on Venezuela. An overview of radio broadcasting in Venezuela describes various aspects and provides…

  20. Radio systems engineering a tutorial approach

    CERN Document Server

    Santos, Héctor J De Los; Ponte, Juan

    2015-01-01

    This book is intended for readers who already have knowledge of devices and circuits for radio-frequency (RF) and microwave communication and are ready to study the systems engineering-level aspects of modern radio communications systems. The authors provide a general overview of radio systems with their components, focusing on the analog parts of the system and their non-idealities. Based on the physical functionality of the various building blocks of a modern radio system, block parameters are derived, which allows the examination of their influence on the overall system performance. The dis

  1. Multimode Communication Protocols Enabling Reconfigurable Radios

    Directory of Open Access Journals (Sweden)

    Berlemann Lars

    2005-01-01

    Full Text Available This paper focuses on the realization and application of a generic protocol stack for reconfigurable wireless communication systems. This focus extends the field of software-defined radios which usually concentrates on the physical layer. The generic protocol stack comprises common protocol functionality and behavior which are extended through specific parts of the targeted radio access technology. This paper considers parameterizable modules of basic protocol functions residing in the data link layer of the ISO/OSI model. System-specific functionality of the protocol software is realized through adequate parameterization and composition of the generic modules. The generic protocol stack allows an efficient realization of reconfigurable protocol software and enables a completely reconfigurable wireless communication system. It is a first step from side-by-side realized, preinstalled modes in a terminal towards a dynamic reconfigurable anymode terminal. The presented modules of the generic protocol stack can also be regarded as a toolbox for the accelerated and cost-efficient development of future communication protocols.

  2. Radio communication for Communications-Based Train Control (CBTC): A tutorial and survey

    DEFF Research Database (Denmark)

    Farooq, Jahanzeb; Soler, José

    2017-01-01

    industry. We believe that this paper fills the much-needed gap. It aims to present a comprehensive tutorial, as well as a survey of the stateof- the-art, of CBTC and the role of radio communication in it. The operation and fundamental components of a CBTC system are discussed. A summary of the evolution...... of the communication technologies used for modern railway signalling is presented. The benefits and drawbacks of using a radio communication technology, particularly Wi-Fi, and the challenges it introduces, are discussed. Best practices in the design of a CBTC radio network and the measures to optimize its......Over the last decade, railway industry has seen a huge transition from conventional railway signalling systems to modern, communication-based signalling systems. Communications-Based Train Control (CBTC) is a modern communication-based system that uses radio communication to transfer timely...

  3. 49 CFR 220.45 - Radio communication shall be complete.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Radio communication shall be complete. 220.45... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.45 Radio communication shall be complete. Any radio communication which is not fully understood...

  4. Radio Gaga? Intra-team communication of Australian Rules Football umpires - effect of radio communication on content, structure and frequency.

    Science.gov (United States)

    Neville, Timothy J; Salmon, Paul M; Read, Gemma J M

    2017-07-31

    Intra-team communication plays an important role in team effectiveness in various domains including sport. As such, it is a key consideration when introducing new tools within systems that utilise teams. The difference in intra-team communication of Australian Rules Football (AFL) umpiring teams was studied when umpiring with or without radio communications technology. A cross-sectional observational study was conducted to analyse the verbal communication of seven umpiring teams (20 participants) grouped according to their experience with radio communication. The results identified that radio communication technology increased the frequency and altered the structure of intra-team communication. Examination of the content of the intra-team communication identified impacts on the 'Big Five' teamwork behaviours and associated coordinating mechanisms. Analysis revealed that the communications utilised did not align with the closed-loop form of communication described in the Big Five model. Implications for teamwork models, coaching and training of AFL umpires are discussed. Practitioner Summary: Assessing the impact of technology on performance is of interest to ergonomics practitioners. The impact of radio communications on teamwork is explored in the highly dynamic domain of AFL umpiring. When given radio technology, intra-team communication increased which supported teamwork behaviours, such as backup behaviour and mutual performance monitoring.

  5. Impact of the Use of Object Request Broker Middleware for Inter-Component Communications in C6416 Digital Signal Processor Based Software Communications Architecture Radio Systems

    Directory of Open Access Journals (Sweden)

    Mohamed I. Yousef

    2012-01-01

    Full Text Available Problem statement: This study presents an in-depth analysis of the performance of Software Communications Architecture (SCA component-based waveform applications in terms of inter-component communications. The main limitation with SCA, in the context of embedded systems, is the additional cost introduced by the use of Object Request Broker (ORB middleware. The ORB middleware handles the interaction between components and objects in SCA distributed environment. This interaction should be highly efficient, due to the real time nature of SCA systems and transparent to the application programmer. Approach: We can achieve high efficiency in SCA systems by enhancing the Inter-Process Communications (IPC mechanisms in Operating systems (OS micro kernels, while we achieve transparency through Interface Definition Language (IDL. Different encoding mechanisms like “External Data Representation (XDR, Network Data Representation (NDR and Common Data Representation (CDR facilitate inter-component communication transparently and efficiently”. Marshalling procedures format data from the local machine representation to common network representations. A most common encoding mechanism for Common Object Request Broker Architecture (CORBA systems is CDR representation. Measurements have been performed with ORBExpress DSP as a CORBA distribution and Open Source SCA Implementation Embedded (OSSIE for SCA implementation. In order to perform these measurements we proposed two metrics for profiling the ORB that are invocation and marshalling. In addition, we propose three elements of data types to evaluate the performance of ORB middleware that are, Basic, Array and Sequence data types. Results: The CORBA bus is really the part, which brings an overhead to the SCA radio systems. This overhead is due to method invocations that have been carried out by ORB middleware. Conclusion: Performance benchmarks of ORBExpress DSP middleware show that, although using CORBA for

  6. Satellite-aided mobile radio concepts study: Concept definition of a satellite-aided mobile and personal radio communication system

    Science.gov (United States)

    Anderson, R. E.

    1979-01-01

    The satellite system requires the use of a large satellite antenna and spacecraft array power of about 12 kW or more depending on the operating frequency. Technology developments needed include large offset reflector multibeam antennas, satellite electrical power sybsystems providing greater than 12 kW of power, signal switching hardware, and linearized efficient solid state amplifiers for the satellite-aided mobile band. Presently there is no frequency assignment for this service, and it is recommended that an allocation be pursued. The satellite system appears to be within reasonable extrapolation of the state of the art. It is further recommended that the satellite-aided system spacecraft definition studies and supporting technology development be initiated.

  7. Radio Frequency (RF) Micro-Electromechanical Systems (MEMS) Switches for Space Communications

    Science.gov (United States)

    Simons, Rainee N.; Ponchak, George E.; Scardelletti, Maximillian C.; Varaljay, Nicholas C.

    2000-01-01

    Micro-electromechanical systems (MEMS) is an emerging technology for radio frequency (RF) systems because it has the potential to dramatically decrease loss and improve efficiency. In this paper, we address the design and fabrication of novel MEMS switches being developed at NASA Glenn Research Center. Two types of switches are being developed: a microstrip series single pole single throw (SPST) switch and a coplanar waveguide (CPW) series SPST and single pole double throw (SPDT) switches. These are being fabricated as an integral part of 50 Ohm microstrip and CPW RF integrated circuits using microfabrication techniques. The construction of the switch relies on a cantilever beam that is partially supported by a dielectric post. The cantilever beam is electro-magnetically actuated. To decrease stiction, a Si3N4 thin film is deposited over the contact area. Thus, when the switch is closed, the ON-state insertion loss is governed by the parallel plate capacitance formed by the two contacts. The isolation in the OFF-state is governed by the parasitic capacitance when the cantilever is in the up position. RF MEMS switches have been demonstrated with 80% lower insertion loss than conventional solid state devices (GaAs Metal Semiconductor Field Effect Transistors (MESFETs) and Silicon PIN diodes) based switches. For example, a conventional GaAs five-bit phase shifter which is required for beam steering in a phased array antenna has approximately 7 dB of insertion loss at 26.5 GHz where as a comparable MEMS based phase shifter is expected to have only 2 dB of insertion loss. This translates into 56% lower power dissipation and therefore decreases the thermal load on the spacecraft and also reduces the power amplifier requirements. These benefits will enable NASA to build the next generation of deep space science crafts and micro/nano satellites.

  8. Realistic Radio Communications in Pilot Simulator Training

    Science.gov (United States)

    Burki-Cohen, Judith; Kendra, Andrew J.; Kanki, Barbara G.; Lee, Alfred T.

    2000-01-01

    Simulators used for total training and evaluation of airline pilots must satisfy stringent criteria in order to assure their adequacy for training and checking maneuvers. Air traffic control and company radio communications simulation, however, may still be left to role-play by the already taxed instructor/evaluators in spite of their central importance in every aspect of the flight environment. The underlying premise of this research is that providing a realistic radio communications environment would increase safety by enhancing pilot training and evaluation. This report summarizes the first-year efforts of assessing the requirement and feasibility of simulating radio communications automatically. A review of the training and crew resource/task management literature showed both practical and theoretical support for the need for realistic radio communications simulation. A survey of 29 instructor/evaluators from 14 airlines revealed that radio communications are mainly role-played by the instructor/evaluators. This increases instructor/evaluators' own workload while unrealistically lowering pilot communications load compared to actual operations, with a concomitant loss in training/evaluation effectiveness. A technology review searching for an automated means of providing radio communications to and from aircraft with minimal human effort showed that while promising, the technology is still immature. Further research and the need for establishing a proof-of-concept are also discussed.

  9. Studying integrated silicon-lens antennas for radio communication systems operated in the 60 GHz frequency band

    Science.gov (United States)

    Artemenko, A. A.; Mal'tsev, A. A.; Maslennikov, R. O.; Sevastyanov, A. G.; Ssorin, V. N.

    2013-01-01

    We consider the development of an integrated lens antenna for LAN radio communication systems operated in the 60 GHz frequency band. The antenna is an extended hemispherical silicon lens. On its flat surface, a microstrip antenna element is located. The use of silicon, which has a dielectric permittivity ɛ = 11.7, as the lens material ensures the maximum range of scanning angles for the minimum axial size of the lens. The approximate analytical formulas, which are used for initial calculations of the lens parameters, allow one to evaluate the basic parameters of the lens antenna integrated with the microstrip antenna element. For further optimizing the parameters of the lens and the antenna element, 3D simulation of the electromagnetic-field distribution was performed. Based on its results, we have developed and manufactured extended hemispherical silicon lenses, which had radii of 6 and 12 mm. The planar microstrip antenna element was manufactured by the low temperature co-fired ceramics (LTCC) technology. The results of simulation and experimental studies of the manufactured prototypes demonstrate that the developed lens antennas has directivities of 17.6 and 23.1 dBi for lenses with radii of 6 and 12 mm, respectively. In this case, the maximum beam deflection angle is achieved, which is equal to 55°, while the permissible decrease in the directivity is no more than 6 dBi compared with the case of a non-deflected beam. The obtained results show that the developed integrated lens antennas can find applications in high-speed radio communication systems operated in the millimeter-wave range.

  10. Inflatable Reflector For Solar Power And Radio Communication

    Science.gov (United States)

    Sercel, Joel; Gilchriest, Carl; Ewell, Rich; Herman, Martin; Rascoe, Daniel L.; Nesmith, Bill J.

    1995-01-01

    Report proposes installation of lightweight inflatable reflector structure aboard spacecraft required to both derive power from sunlight and communicate with Earth by radio when apparent position of Earth is at manageably small angle from line of sight to Sun. Structure contains large-aperture paraboloidal reflector aimed toward Sun and concentrates sunlight onto photovoltaic power converter and acts as main reflector of spacecraft radio-communication system.

  11. Cognitive Radio Networks for Tactical Wireless Communications

    Science.gov (United States)

    2014-12-01

    APs work as wireless routers and form a wireless backbone network. The MSs can either access the BSs/APs directly, or use other MSs as multi-hop...Cognitive radio networks for tactical wireless communications Helen Tang; Susan Watson DRDC – Ottawa Research Centre Defence Research and...Development Canada Scientific Report DRDC-RDDC-2014-R185 December 2014 Cognitive radio networks for tactical wireless communications Helen Tang

  12. Socio-Economic Aspects of National Communication Systems. I. Radio Broadcasting in Austria. Communication and Society, 10.

    Science.gov (United States)

    Signitzer, Benno; Luger, Kurt

    The first in a series that examines the role of radio broadcasting in the process of socioeconomic and cultural change in three countries with different types of broadcasting organization--Austria, Czechoslovakia, and Venezuela--this volume focuses on Austria. It deals with the cultural implications of broadcasting structures and their ownership…

  13. Socio-Economic Aspects of National Communication Systems: II. Radio Broadcasting in Czechoslovakia. Communication and Society, 11.

    Science.gov (United States)

    Bunzlova, Alice; Slovak, Leopold

    The second in a series that examines the role of radio broadcasting in the process of socioeconomic and cultural change in three countries with different types of broadcasting organization--Austria, Czechoslovakia, and Venezuela--this volume focuses on Czechoslovakia. It deals with the cultural implications of broadcasting structures and their…

  14. Radio for formal education and for development communication.

    Science.gov (United States)

    Jamison, D T

    1978-09-01

    A substantial body of literature documents the successful use of open radio broadcasting, radio campaigns, and radio-listening groups in nonformal education and other aspects of development communication. The 4 alternative strategies for using radio in formal education -- using radio to enrich learning, direct instruction, extending in-school education, and distance learning -- need to be assessed in terms of users' needs. The use of radio to enrich in-school education holds little promise for major improvements, but the potential for the use of radio in direct instruction in 1 or more subjects is promising and presents a strong challenge to educators. Case studies of 2 Mexican projects to extend school in order to expand the rural population's access to information and schools were disappointing. Both projects showed that radio could teach about as effectively as traditional elementary school teachers, but neither expanded beyond the pilot stage. Better financing and a firmer government commitment might have made a difference. The use of radio in formal education as a component of a distance-learning system has been successful in Kenya and the Dominican Republic, among other places. The best use of open broadcast is to transmit an interesting message; the most appropriate use of listening-group strategies -- radio schools, farm forums, and radio animation -- are to promote more complex and longterm changes. Communication planners need to be aware that radio can be used in numerous ways in response to a variety of goals. 4 projects are reviewed to illustrate instances in which radio has realized its goals with special success -- the Kenyan health broadcasts, the radio program that used nutrition "ads," the Guatemalan agricultural information programs, and the Tanzania radio campaigns. These projects show that the development goals being promoted and the special characteristics of the project determine the strategy, its effects, and its transferability.

  15. Transmit-reference methods in software defined radio platforms for communication in harsh propagation environments and systems thereof

    Energy Technology Data Exchange (ETDEWEB)

    Dowla, Farid; Nekoogar, Faranak

    2017-01-03

    A method for adaptive Radio Frequency (RF) jamming according to one embodiment includes dynamically monitoring a RF spectrum; detecting any undesired signals in real time from the RF spectrum; and sending a directional countermeasure signal to jam the undesired signals. A method for adaptive Radio Frequency (RF) communications according to another embodiment includes transmitting a data pulse in a RF spectrum; and transmitting a reference pulse separated by a predetermined period of time from the data pulse; wherein the data pulse is modulated with data, wherein the reference pulse is unmodulated. A method for adaptive Radio Frequency (RF) communications according to yet another embodiment includes receiving a data pulse in a RF spectrum; and receiving a reference pulse separated in time from the data pulse, wherein the data pulse is modulated with data, wherein the reference pulse is unmodulated; and demodulating the pulses.

  16. Radio communications with extra-terrestrial civilizations

    Science.gov (United States)

    Kotelnikov, V. A.

    1974-01-01

    Communications between civilizations within our galaxy at the present level of radio engineering is possible, although civilizations must begin to search for each other to achieve this. If an extra-terrestrial civilization possessing a technology at our level wishes to make itself known and will transmit special radio signals to do this, then it can be picked up by us at a distance of several hundreds of light years using already existing radio telescopes and specially built radio receivers. If it wishes, this civilization can also send us information without awaiting our answer.

  17. [Effects of radio- and microwaves emitted by wireless communication devices on the functions of the nervous system selected elements].

    Science.gov (United States)

    Politański, Piotr; Bortkiewicz, Alicja; Zmyślony, Marek

    Nervous system is the most "electric" system in the human body. The research of the effects of electromagnetic fields (EMFs) of different frequencies on its functioning have been carried out for years. This paper presents the results of the scientific literature review on the EMF influence on the functioning of the human nervous system with a particular emphasis on the recent studies of the modern wireless communication and data transmission systems. In the majority of the analyzed areas the published research results do not show EMF effects on the nervous system, except for the influence of GSM telephony signal on resting EEG and EEG during patients' sleep and the influence of radiofrequency EMF on the cardiovascular regulation. In other analyzed areas (EMF impact on sleep, the evoked potentials and cognitive processes), there are no consistent results supporting any influence of electromagnetic fields. Neurophysiological studies of the effect of radio- and microwaves on the brain functions in humans are still considered inconclusive. This is among others due to, different exposure conditions, a large number of variables tested, deficiencies in repeatability of research and statistical uncertainties. However, methodological guidelines are already available giving a chance of unifying research that definitely needs to be continued in order to identify biophysical mechanisms of interaction between EMFs and the nervous system. One of the EMF research aspects, on which more and more attention is paid, are inter-individual differences. Med Pr 2016;67(3):411-421.

  18. 47 CFR 32.2231 - Radio systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Radio systems. 32.2231 Section 32.2231 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2231 Radio systems. (a...

  19. Performance evaluation of cognitive radio in advanced metering infrastructure communication

    Science.gov (United States)

    Hiew, Yik-Kuan; Mohd Aripin, Norazizah; Din, Norashidah Md

    2016-03-01

    Smart grid is an intelligent electricity grid system. A reliable two-way communication system is required to transmit both critical and non-critical smart grid data. However, it is difficult to locate a huge chunk of dedicated spectrum for smart grid communications. Hence, cognitive radio based communication is applied. Cognitive radio allows smart grid users to access licensed spectrums opportunistically with the constraint of not causing harmful interference to licensed users. In this paper, a cognitive radio based smart grid communication framework is proposed. Smart grid framework consists of Home Area Network (HAN) and Advanced Metering Infrastructure (AMI), while AMI is made up of Neighborhood Area Network (NAN) and Wide Area Network (WAN). In this paper, the authors only report the findings for AMI communication. AMI is smart grid domain that comprises smart meters, data aggregator unit, and billing center. Meter data are collected by smart meters and transmitted to data aggregator unit by using cognitive 802.11 technique; data aggregator unit then relays the data to billing center using cognitive WiMAX and TV white space. The performance of cognitive radio in AMI communication is investigated using Network Simulator 2. Simulation results show that cognitive radio improves the latency and throughput performances of AMI. Besides, cognitive radio also improves spectrum utilization efficiency of WiMAX band from 5.92% to 9.24% and duty cycle of TV band from 6.6% to 10.77%.

  20. At the Dawn of Radio Communications

    Directory of Open Access Journals (Sweden)

    V. P. Samokhin

    2017-01-01

    Full Text Available A brief review of the history of radio communications, which were used before the advent of humanity tubes, in the context of the essays in the series "At the root of media", published in the "History of Technical Progress" section of the supplement to our journal "Science and Education". The review covers the main stages of the development of spark radio-telegraph systems, the creation of the first powerful arc and electric machine generators of non-stopping oscillations of the carrier frequency for radiotelephony and the detection features. The first experiments of Mahlon Loomis, scientific and technical achievements of James Maxwell, Henry Hertz, Eduard Branly, Alexander Popov, Oliver Lodge, Jagadish Bosch, Karl Brown, Lee de Forest, Louis Austin, Herman Simon, William Duddel, Valdemar Paulsen, Ernst Alexander, Valentin Vologdin, Semyon Eisenstein and other creators of the nascent radio engineering. Particular attention is paid to the intersections of their work with the work of Thomas Edison, Nikola Tesla, Guglielmo Marconi, Reginald Fessenden and other heroes of our essays.

  1. The use of cell phones and radio communication systems to reduce delays in getting help for pregnant women in low- and middle-income countries: a scoping review

    Directory of Open Access Journals (Sweden)

    Sunday O. Oyeyemi

    2015-09-01

    Full Text Available Background: Delays in getting medical help are important factors in the deaths of many pregnant women and unborn children in the low- and middle-income countries (LMIC. Studies have suggested that the use of cell phones and radio communication systems might reduce such delays. Objectives: We review the literature regarding the impact of cell phones and radio communication systems on delays in getting medical help by pregnant women in the LMIC. Design: Cochrane Library, PubMed, Maternity and Infant care (Ovid, Web of Science (ISI, and Google Scholar were searched for studies relating to the use of cell phones for maternal and child health services, supplemented with hand searches. We included studies in LMIC and in English involving the simple use of cell phones (or radio communication to either make calls or send text messages. Results: Fifteen studies met the inclusion criteria. All the studies, while of various designs, demonstrated positive contributory effects of cell phones or radio communication systems in reducing delays experienced by pregnant women in getting medical help. Conclusions: While the results suggested that cell phones could contribute in reducing delays, more studies of a longer duration are needed to strengthen the finding.

  2. Communication Systems Analysis Laboratory (CSAL)

    Data.gov (United States)

    Federal Laboratory Consortium — CSAL conducts electronic warfare investigations of radio frequency communication systems with respect to current and emerging electronic warfare threats. CSAL uses...

  3. HF radio systems and circuits

    CERN Document Server

    Sabin, William

    1998-01-01

    A comprehensive reference for the design of high frequency communications systems and equipment. This revised edition is loaded with practical data, much of which cannot be found in other reference books. Its approach to the subject follows the needs of an engineer from system definition and performance requirements down to the individual circuit elements that make up radio transmitters and receivers. The accompanying disk contains updated software on filters, matching networks and receiver analysis. SciTech Publishing also provides many other products related to Communication Systems Design.

  4. An orbital angular momentum radio communication system optimized by intensity controlled masks effectively: Theoretical design and experimental verification

    Science.gov (United States)

    Gao, Xinlu; Huang, Shanguo; Wei, Yongfeng; Zhai, Wensheng; Xu, Wenjing; Yin, Shan; Zhou, Jing; Gu, Wanyi

    2014-12-01

    A system of generating and receiving orbital angular momentum (OAM) radio beams, which are collectively formed by two circular array antennas (CAAs) and effectively optimized by two intensity controlled masks, is proposed and experimentally investigated. The scheme is effective in blocking of the unwanted OAM modes and enhancing the power of received radio signals, which results in the capacity gain of system and extended transmission distance of the OAM radio beams. The operation principle of the intensity controlled masks, which can be regarded as both collimator and filter, is feasible and simple to realize. Numerical simulations of intensity and phase distributions at each key cross-sectional plane of the radio beams demonstrate the collimated results. The experimental results match well with the theoretical analysis and the receive distance of the OAM radio beam at radio frequency (RF) 20 GHz is extended up to 200 times of the wavelength of the RF signals, the measured distance is 5 times of the original measured distance. The presented proof-of-concept experiment demonstrates the feasibility of the system.

  5. 49 CFR 220.51 - Radio communications and signal indications.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Radio communications and signal indications. 220... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.51 Radio communications and signal indications. (a) No information may be...

  6. Adaptive Baseband Processing Techniques for Cognitive Radio Systems

    NARCIS (Netherlands)

    Budiarjo, I.

    2009-01-01

    Cognitive Radio is a new paradigm in the wireless communications. It puts the intelligence and awareness dimension to the radio communication system. A Cognitive Radio system will be aware of the changing condition in its environment. The awareness in this thesis is related to the spectrum and the c

  7. Spanish Basic Course: Radio Communications Procedures, USAF.

    Science.gov (United States)

    Defense Language Inst., Washington, DC.

    This guide to radio communication procedures is offered in Spanish and English as a means of securing a closer working relationship among United States Air Force personnel and Latin American aviators and technicians. Eight dialogues concerning routine flight procedures and aerospace technology are included. It is suggested that two rated students…

  8. Towards Ultrahigh Speed Impulse Radio THz Wireless Communications

    DEFF Research Database (Denmark)

    Yu, Xianbin; Galili, Michael; Morioka, Toshio

    2015-01-01

    THz impulse radio technologies promise a new paradigm of fast wireless access with simplified wireless reception. However, huge loss of propagating broad bandwidth THz impulse radio signals limits THz wireless transmission distance and reduces the achievable link data rates. In this paper, we...... evaluate the realistic throughput and accessible wireless range of a THz impulse radio communication link based on a uni-travelling photodiode (UTC-PD) as THz emitter and a photoconductive antenna (PCA) as THz receiver. The impact of highly frequency-selective THz channel and the noise in the system...

  9. On Achievable Performance of Cognitive Radio Systems

    CERN Document Server

    Haddad, Majed; Hayar, Aawatif Menouni

    2007-01-01

    In this contribution, we investigate the idea of using cognitive radio to reuse locally unused spectrum to increase the total system capacity. We consider a multiband/wideband system in which the primary and cognitive users wish to communicate to different receivers, subject to mutual interference and assume that each user knows only his channel and the unused spectrum through adequate sensing. Under this scheme, a cognitive radio will listen to the channel and, if sensed idle, will transmit during the voids. Within this setting, we provide two simple methods for sensing the idle sub-bands over the total bandwidth. We impose the constraint that users successively transmit over available bands through proper water filling. For the first time, our study has quantified the achievable gain of using cognitive radio with respect to classical radio devices and derive the total spectral efficiency as well as the maximum number of possible pairwise communications of such a cognitive radio system. We finally show that ...

  10. Radio data archiving system

    Science.gov (United States)

    Knapic, C.; Zanichelli, A.; Dovgan, E.; Nanni, M.; Stagni, M.; Righini, S.; Sponza, M.; Bedosti, F.; Orlati, A.; Smareglia, R.

    2016-07-01

    Radio Astronomical Data models are becoming very complex since the huge possible range of instrumental configurations available with the modern Radio Telescopes. What in the past was the last frontiers of data formats in terms of efficiency and flexibility is now evolving with new strategies and methodologies enabling the persistence of a very complex, hierarchical and multi-purpose information. Such an evolution of data models and data formats require new data archiving techniques in order to guarantee data preservation following the directives of Open Archival Information System and the International Virtual Observatory Alliance for data sharing and publication. Currently, various formats (FITS, MBFITS, VLBI's XML description files and ancillary files) of data acquired with the Medicina and Noto Radio Telescopes can be stored and handled by a common Radio Archive, that is planned to be released to the (inter)national community by the end of 2016. This state-of-the-art archiving system for radio astronomical data aims at delegating as much as possible to the software setting how and where the descriptors (metadata) are saved, while the users perform user-friendly queries translated by the web interface into complex interrogations on the database to retrieve data. In such a way, the Archive is ready to be Virtual Observatory compliant and as much as possible user-friendly.

  11. Shipboard Radio Frequency and Free Space Optics Communications System using an Airborne Relay

    Science.gov (United States)

    2005-09-01

    gain for FSO systems has the potential to be several orders of magnitude greater than RF gain by virtue of the 21λ factor. An optical antenna with... optical antenna , in this case, has a 40 dB advantage, ten-thousand times the gain, despite its smaller dimensions. 1. Transmit Gain A parabolic...3rd Edition. 2001. [19] Klein, B. J., and Degnan, J. J. “ Optical Antenna Gain. 1: Transmitting Antennas.” Applied Optics, Vol. 13, No. 9

  12. Integrated Radio and Optical Communication (iROC)

    Science.gov (United States)

    Raible, Daniel; Romanofsky, Robert; Pease, Gary; Kacpura, Thomas

    2016-01-01

    This is an overview of the Integrated Radio and Optical Communication (iROC) Project for Space Communication and Navigation Industry Days. The Goal is to develop and demonstrate new, high payoff space technologies that will promote mission utilization of optical communications, thereby expanding the capabilities of NASA's exploration, science, and discovery missions. This is an overview that combines the paramount features of select deep space RF and optical communications elements into an integrated system, scalable from deep space to near earth. It will realize Ka-band RF and 1550 nanometer optical capability. The approach is to prototype and demonstrate performance of key components to increase to TRL-5, leading to integrated hybrid communications system demonstration to increase to TRL-5, leading to integrated hybrid communications system demonstration.

  13. Unmanned Aviation Systems Models of the Radio Communications Links: Study Results - Appendices Annex 2. Volume 1 and Volume 2

    Science.gov (United States)

    Birr, Richard B.; Spencer, Roy; Murray, Jennifer; Lash, Andrew

    2013-01-01

    This report describes the analysis of communications between the Control Station and an Unmanned Aircraft (UA) flying in the National Airspace System (NAS). This work is based on the RTCA SC-203 Operational Services and Environment Description (OSED). The OSED document seeks to characterize the highly different attributes of all UAs navigating the airspace and define their relationship to airspace users, air traffic services, and operating environments of the NAS. One goal of this report is to lead to the development of Minimum Aviation System Performance Standards for Control and Communications. This report takes the nine scenarios found in the OSED and analyzes the communication links.

  14. Perencanaan dan analisis kehandalan sistem komunikasi radio microwave tampak pandang pada pita frekuensi 12750-13250 MHz [Planning and analysis of the reliability of line of sight microwave radio communication system on 12750-13250 MHz band

    Directory of Open Access Journals (Sweden)

    Ahmad Hasyim

    2016-12-01

    Full Text Available Propagasi gelombang radio dapat diartikan sebagai proses perambatan gelombang radio dari pemancar ke penerima. Gelombang ini akan merambat melalui udara bebas menuju antena penerima dan mengalami redaman di sepanjang lintansannya,  redaman perangkat dan saluran transmisi, sehingga ketika sampai di antena penerima, energi sinyal sudah sangat lemah. Line of sight    (LOS merupakan salah satu jenis propagasi di mana diantara stasiun pengirim dan stasiun penerima  tidak terdapat penghalang. Kendala geografis dan kelengkungan bumi menyebabkan adanya keterbatasan untuk transmisi line of sight, namun masalah ini secara umum dapat dikurangi melalui perencanaan, perhitungan dan penggunaan teknologi tambahan. Dalam perencanaan sistem komunikasi radio, kinerja LOS perlu direncanakan cadangan daya akibat fluktuasi sinyal serta analisis kehandalannya. Sistem radio gelombang mikro digital antar titik yang menggunakan  frekuensi 13 GHz dengan modulasi 16 QAM, bit rate 140 MBps,dan  noise figure 0,7 dB memerlukan daya pancar -4,488 dBm, fading margin sebesar 85,51 dB dan kehandalannya sebesar 99,9999999%.*****Radio wave propagation can be defined as the process of propagation of radio waves from the transmitter to the receiver. These waves will propagate through free air towards the receiver antena with experienced curbs along the tracks, so when it arrive at the receiver antena, the signal energy is very slow. Line of sight (LOS is one kind of propagation where no obstacles found between the transmitter and the receiver station. Geographical constraints and the curvature of the earth bring limitations to the line of sight transmission, but this problem can generally be reduced through planning, calculation and use of additional technologies. In a radio communication system planning, LOS performance needs to be planned caused by signal fluctuations and reliability. Digital microwave point to point radio systems using 13 GHz of spectrum, 16 QAM of

  15. Software-Defined Ultra-wideband Radio Communications: A New RF Technology for Emergency Response Applications

    Energy Technology Data Exchange (ETDEWEB)

    Nekoogar, F; Dowla, F

    2009-10-19

    Reliable wireless communication links for local-area (short-range) and regional (long-range) reach capabilities are crucial for emergency response to disasters. Lack of a dependable communication system can result in disruptions in the situational awareness between the local responders in the field and the emergency command and control centers. To date, all wireless communications systems such as cell phones and walkie-talkies use narrowband radio frequency (RF) signaling for data communication. However, the hostile radio propagation environment caused by collapsed structures and rubble in various disaster sites results in significant degradation and attenuation of narrowband RF signals, which ends up in frequent communication breakdowns. To address the challenges of reliable radio communication in disaster fields, we propose an approach to use ultra-wideband (UWB) or wideband RF waveforms for implementation on Software Defined Radio (SDR) platforms. Ultra-wideband communications has been proven by many research groups to be effective in addressing many of the limitations faced by conventional narrowband radio technologies. In addition, LLNL's radio and wireless team have shown significant success in field deployment of various UWB communications system for harsh environments based on LLNL's patented UWB modulation and equalization techniques. Furthermore, using software defined radio platform for UWB communications offers a great deal of flexibility in operational parameters and helps the radio system to dynamically adapt itself to its environment for optimal performance.

  16. Amateur Radio Communication Technology Contingency Communication in Emergency Situation

    Directory of Open Access Journals (Sweden)

    Johar Azlee

    2017-01-01

    Full Text Available Disasters cannot be avoided, but efforts can be made to reduce death, injuries and property damages through better communications and better planning to deal with it before it happen. Thus we need to adopt available technology, like the Amateur Radio Communication Technology (ACT, to face this problem. These include providing awareness, training and support for the communities who adopt the technology for Emergency Communication (EC. Through having more qualified Amateur Radio Communities (ARC in the adoption of the ARCT, we would be able to improve the communication before, during and after the disasters struck. There are many challenges and issues in the adoption of the ARCT that would part of this study. This article also describes several case studies of communication failure during Hurricane Katrina (2005 in the USA, as well as disasters in several other countries and Malaysia. The tragedies led to failure of existing communication infrastructure, and were reprieved by the help of the voluntary ARC to support the relief agencies in the evacuation and assistance the disaster victims. Therefore, this article will highlight the significant issues that influence the adoption of ARCT in EC.

  17. Radio Science from an Optical Communications Signal

    Science.gov (United States)

    Moision, Bruce; Asmar, Sami; Oudrhiri, Kamal

    2013-01-01

    NASA is currently developing the capability to deploy deep space optical communications links. This creates the opportunity to utilize the optical link to obtain range, doppler, and signal intensity estimates. These may, in turn, be used to complement or extend the capabilities of current radio science. In this paper we illustrate the achievable precision in estimating range, doppler, and received signal intensity of an non-coherent optical link (the current state-of-the-art for a deep-space link). We provide a joint estimation algorithm with performance close to the bound. We draw comparisons to estimates based on a coherent radio frequency signal, illustrating that large gains in either precision or observation time are possible with an optical link.

  18. Implantable radio frequency identification sensors: wireless power and communication.

    Science.gov (United States)

    Hutchens, Chriswell; Rennaker, Robert L; Venkataraman, Srinivasan; Ahmed, Rehan; Liao, Ran; Ibrahim, Tamer

    2011-01-01

    There are significant technical challenges in the development of a fully implantable wirelessly powered neural interface. Challenges include wireless transmission of sufficient power to the implanted device to ensure reliable operation for decades without replacement, minimizing tissue heating, and adequate reliable communications bandwidth. Overcoming these challenges is essential for the development of implantable closed loop system for the treatment of disorders ranging from epilepsy, incontinence, stroke and spinal cord injury. We discuss the development of the wireless power, communication and control for a Radio-Frequency Identification Sensor (RFIDS) system with targeted power range for a 700 mV, 30 to 40 uA load attained at -2 dBm.

  19. Software Defined Radio Architecture Contributions to Next Generation Space Communications

    Science.gov (United States)

    Kacpura, Thomas J.; Eddy, Wesley M.; Smith, Carl R.; Liebetreu, John

    2015-01-01

    systems, as well as those communications and navigation systems operated by international space agencies and civilian and government agencies. In this paper, we review the philosophies, technologies, architectural attributes, mission services, and communications capabilities that form the structure of candidate next-generation integrated communication architectures for space communications and navigation. A key area that this paper explores is from the development and operation of the software defined radio for the NASA Space Communications and Navigation (SCaN) Testbed currently on the International Space Station (ISS). Evaluating the lessons learned from development and operation feed back into the communications architecture. Leveraging the reconfigurability provides a change in the way that operations are done and must be considered. Quantifying the impact on the NASA Space Telecommunications Radio System (STRS) software defined radio architecture provides feedback to keep the standard useful and up to date. NASA is not the only customer of these radios. Software defined radios are developed for other applications, and taking advantage of these developments promotes an architecture that is cost effective and sustainable. Developments in the following areas such as an updated operating environment, higher data rates, networking and security can be leveraged. The ability to sustain an architecture that uses radios for multiple markets can lower costs and keep new technology infused.

  20. Uzaybimer Radio Telescope Control System

    Science.gov (United States)

    Balbay, R.; Öz, G. K.; Arslan, Ö.; Özeren, F. F.; Küçük, İ.

    2016-12-01

    A 13 meters former NATO radar is being converted into a radio telescope. The radio telescope is controlled by a system which has been developed at UZAYBİMER. The Telescope Control System(TCS) has been designed using modern industrial systems. TCS has been developed in LabView platform in which works Windows embedded OS. The position feedback used on radio telescopes is an industrial EtherCAT standard. ASCOM library is used for astronomical calculations.

  1. Rhetorical Perspectives in Radio Communications: The Speaker and the Loudspeaker.

    Science.gov (United States)

    Godfrey, Donald G.

    Radio rhetoric is set apart from traditional rhetoric by the efficacy it commands. This study focuses on rhetorical perspective in radio communication, noting 10 identifiable aspects of radio rhetoric noteworthy in undertaking rhetorical criticism: (1) the pressures of federal regulations which require balanced presentation affect preparation; (2)…

  2. Voice Communications Over Packet Radio Networks.

    Science.gov (United States)

    1985-03-01

    standpoint, the major difference between telephone networks and packet radio networks concerns the availabilty of time slots over each frame. The...mentioning that simulations require large amounts of detailed knowledge about the structure of the system and about patterns of usage . Simulation is...proposed time slot algorithm adopts. Moreover, the proposed time slot scheme may give more uniform usage of time slots in each time frame. In addition

  3. Networked Operations of Hybrid Radio Optical Communications Satellites

    Science.gov (United States)

    Hylton, Alan; Raible, Daniel

    2014-01-01

    In order to address the increasing communications needs of modern equipment in space, and to address the increasing number of objects in space, NASA is demonstrating the potential capability of optical communications for both deep space and near-Earth applications. The Integrated Radio Optical Communications (iROC) is a hybrid communications system that capitalizes on the best of both the optical and RF domains while using each technology to compensate for the other's shortcomings. Specifically, the data rates of the optical links can be higher than their RF counterparts, whereas the RF links have greater link availability. The focus of this paper is twofold: to consider the operations of one or more iROC nodes from a networking point of view, and to suggest specific areas of research to further the field. We consider the utility of Disruption Tolerant Networking (DTN) and the Virtual Mission Operation Center (VMOC) model.

  4. Experimental radio frequency link for Ka-band communications applications

    Science.gov (United States)

    Fujikawa, Gene; Conray, Martin J.; Saunders, Alan L.; Pope, Dale E.

    1988-01-01

    An experimental radio frequency link has been demonstrated to provide two-way communication between a remote user ground terminal and a ground-based Ka-band transponder. Bit-error-rate performance and radio frequency characteristics of the communication link were investigated.

  5. A COTS RF/Optical Software Defined Radio for the Integrated Radio and Optical Communications Test Bed

    Science.gov (United States)

    Nappier, Jennifer M.; Zeleznikar, Daniel J.; Wroblewski, Adam C.; Tokars, Roger P.; Schoenholz, Bryan L.; Lantz, Nicholas C.

    2017-01-01

    The Integrated Radio and Optical Communications (iROC) project at the National Aeronautics and Space Administration (NASA) is investigating the merits of a hybrid radio frequency (RF) and optical communication system for deep space missions. In an effort to demonstrate the feasibility and advantages of a hybrid RF/Optical software defined radio (SDR), a laboratory prototype was assembled from primarily commercial-off-the-shelf (COTS) hardware components. This COTS platform has been used to demonstrate simultaneous transmission of the radio and optical communications waveforms through to the physical layer (telescope and antenna). This paper details the hardware and software used in the platform and various measures of its performance. A laboratory optical receiver platform has also been assembled in order to demonstrate hybrid free space links in combination with the transmitter.

  6. Science on air: the role of radio in science communication

    Directory of Open Access Journals (Sweden)

    Merzagora Matteo

    2004-12-01

    Full Text Available The international symposium “Science on air: the role of radio in science communication” was held inTrieste on 1 and 2 October, 2004. To our knowledge, it is the first conference ever specifically held on science on radio, and it is certainly the first time science radio journalists, researchers, and mediaexperts from 16 different countries met to discuss their journalistic practice and the role of radio in science communication.The main results are presented in this article.

  7. Energy-Aware Cognitive Radio Systems

    KAUST Repository

    Bedeer, Ebrahim

    2016-01-15

    The concept of energy-aware communications has spurred the interest of the research community in the most recent years due to various environmental and economical reasons. It becomes indispensable for wireless communication systems to shift their resource allocation problems from optimizing traditional metrics, such as throughput and latency, to an environmental-friendly energy metric. Although cognitive radio systems introduce spectrum efficient usage techniques, they employ new complex technologies for spectrum sensing and sharing that consume extra energy to compensate for overhead and feedback costs. Considering an adequate energy efficiency metric—that takes into account the transmit power consumption, circuitry power, and signaling overhead—is of momentous importance such that optimal resource allocations in cognitive radio systems reduce the energy consumption. A literature survey of recent energy-efficient based resource allocations schemes is presented for cognitive radio systems. The energy efficiency performances of these schemes are analyzed and evaluated under power budget, co-channel and adjacent-channel interferences, channel estimation errors, quality-of-service, and/or fairness constraints. Finally, the opportunities and challenges of energy-aware design for cognitive radio systems are discussed.

  8. RFID Transponders' Radio Frequency Emissions in Aircraft Communication and Navigation Radio Bands

    Science.gov (United States)

    Nguyen, Truong X.; Ely, Jay J.; Williams, Reuben A.; Koppen, Sandra V.; Salud, Maria Theresa P.

    2006-01-01

    Radiated emissions in aircraft communication and navigation bands are measured from several active radio frequency identification (RFID) tags. The individual tags are different in design and operations. They may also operate in different frequency bands. The process for measuring the emissions is discussed, and includes tag interrogation, reverberation chamber testing, and instrument settings selection. The measurement results are described and compared against aircraft emission limits. In addition, interference path loss for the cargo bays of passenger aircraft is measured. Cargo bay path loss is more appropriate for RFID tags than passenger cabin path loss. The path loss data are reported for several aircraft radio systems on a Boeing 747 and an Airbus A320.

  9. 49 CFR 220.43 - Radio communications consistent with federal regulations and railroad operating rules.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Radio communications consistent with federal... Radio and Wireless Communication Procedures § 220.43 Radio communications consistent with federal regulations and railroad operating rules. Radio communication shall not be used in connection with a...

  10. 49 CFR 220.37 - Testing radio and wireless communication equipment.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Testing radio and wireless communication equipment... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.37 Testing radio and wireless communication equipment. (a) Each radio, and...

  11. Ultra-Wideband Radio Frequency Identification Systems

    CERN Document Server

    Nekoogar, Faranak

    2012-01-01

    Ultra-Wideband Radio Frequency Identification Systems describes the essentials of radio frequency identification systems as well as their target markets. The authors provide a study of commercially available RFID systems and characterizes their performance in terms of read range and reliability in the presence of conductive and dielectric materials. The capabilities and limitations of some commercial RFID systems are reported followed by comprehensive discussions of the advantages and challenges of using ultra-wideband technology for tag/reader communications. The book presents practical aspects of UWB RFID system such as: pulse generation, remote powering, tag and reader antenna design, as well as special applications of  UWB RFIDs in a simple and easy-to-understand language.

  12. Incorporating the Campus Radio Station into Your Emergency Communications Plan

    Science.gov (United States)

    Johnson, Thomas C.

    2008-01-01

    Radio stations have been a mainstay of American life since the 1920s. Broadcasting primarily over AM and FM frequencies, American radio stations have been used to provide entertainment, news, weather, and advertising to the public. Beginning in 1963 and continuing until 1997, local radio stations were part of the Emergency Broadcast System (EBS)…

  13. Hybrid spread spectrum radio system

    Science.gov (United States)

    Smith, Stephen F [London, TN; Dress, William B [Camas, WA

    2010-02-09

    Systems and methods are described for hybrid spread spectrum radio systems. A method, includes receiving a hybrid spread spectrum signal including: fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

  14. Reconfigurable/Reprogrammable Communications Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA's latest effort in developing a common platform for space communication and navigation systems is the Space Telecommunications Radio System (STRS) standard. It...

  15. Integrated Power, Avionics, and Software (iPAS) Space Telecommunications Radio System (STRS) Radio User's Guide -- Advanced Exploration Systems (AES)

    Science.gov (United States)

    Roche, Rigoberto; Shalkhauser, Mary Jo Windmille

    2017-01-01

    The Integrated Power, Avionics and Software (IPAS) software defined radio (SDR) was implemented on the Reconfigurable, Intelligently-Adaptive Communication System (RAICS) platform, for radio development at NASA Johnson Space Center. Software and hardware description language (HDL) code were delivered by NASA Glenn Research Center for use in the IPAS test bed and for development of their own Space Telecommunications Radio System (STRS) waveforms on the RAICS platform. The purpose of this document is to describe how to setup and operate the IPAS STRS Radio platform with its delivered test waveform.

  16. Localization and cooperative communication methods for cognitive radio

    Science.gov (United States)

    Duval, Olivier

    We study localization of nearby nodes and cooperative communication for cognitive radios. Cognitive radios sensing their environment to estimate the channel gain between nodes can cooperate and adapt their transmission power to maximize the capacity of the communication between two nodes. We study the end-to-end capacity of a cooperative relaying scheme using orthogonal frequency-division modulation (OFDM) modulation, under power constraints for both the base station and the relay station. The relay uses amplify-and-forward and decode-and-forward cooperative relaying techniques to retransmit messages on a subset of the available subcarriers. The power used in the base station and the relay station transmitters is allocated to maximize the overall system capacity. The subcarrier selection and power allocation are obtained based on convex optimization formulations and an iterative algorithm. Additionally, decode-and-forward relaying schemes are allowed to pair source and relayed subcarriers to increase further the capacity of the system. The proposed techniques outperforms non-selective relaying schemes over a range of relay power budgets. Cognitive radios can be used for opportunistic access of the radio spectrum by detecting spectrum holes left unused by licensed primary users. We introduce a spectrum holes detection approach, which combines blind modulation classification, angle of arrival estimation and number of sources detection. We perform eigenspace analysis to determine the number of sources, and estimate their angles of arrival (AOA). In addition, we classify detected sources as primary or secondary users with their distinct second-orde one-conjugate cyclostationarity features. Extensive simulations carried out indicate that the proposed system identifies and locates individual sources correctly, even at -4 dB signal-to-noise ratios (SNR). In environments with a high density of scatterers, several wireless channels experience nonline-of-sight (NLOS

  17. Radio Synthesis Imaging - A High Performance Computing and Communications Project

    Science.gov (United States)

    Crutcher, Richard M.

    The National Science Foundation has funded a five-year High Performance Computing and Communications project at the National Center for Supercomputing Applications (NCSA) for the direct implementation of several of the computing recommendations of the Astronomy and Astrophysics Survey Committee (the "Bahcall report"). This paper is a summary of the project goals and a progress report. The project will implement a prototype of the next generation of astronomical telescope systems - remotely located telescopes connected by high-speed networks to very high performance, scalable architecture computers and on-line data archives, which are accessed by astronomers over Gbit/sec networks. Specifically, a data link has been installed between the BIMA millimeter-wave synthesis array at Hat Creek, California and NCSA at Urbana, Illinois for real-time transmission of data to NCSA. Data are automatically archived, and may be browsed and retrieved by astronomers using the NCSA Mosaic software. In addition, an on-line digital library of processed images will be established. BIMA data will be processed on a very high performance distributed computing system, with I/O, user interface, and most of the software system running on the NCSA Convex C3880 supercomputer or Silicon Graphics Onyx workstations connected by HiPPI to the high performance, massively parallel Thinking Machines Corporation CM-5. The very computationally intensive algorithms for calibration and imaging of radio synthesis array observations will be optimized for the CM-5 and new algorithms which utilize the massively parallel architecture will be developed. Code running simultaneously on the distributed computers will communicate using the Data Transport Mechanism developed by NCSA. The project will also use the BLANCA Gbit/s testbed network between Urbana and Madison, Wisconsin to connect an Onyx workstation in the University of Wisconsin Astronomy Department to the NCSA CM-5, for development of long

  18. Reconfigurable radio systems network architectures and standards

    CERN Document Server

    Iacobucci, Maria Stella

    2013-01-01

    This timely book provides a standards-based view of the development, evolution, techniques and potential future scenarios for the deployment of reconfigurable radio systems.  After an introduction to radiomobile and radio systems deployed in the access network, the book describes cognitive radio concepts and capabilities, which are the basis for reconfigurable radio systems.  The self-organizing network features introduced in 3GPP standards are discussed and IEEE 802.22, the first standard based on cognitive radio, is described. Then the ETSI reconfigurable radio systems functional ar

  19. Radio Wave Propagation Handbook for Communication on and Around Mars

    Science.gov (United States)

    Ho, Christian; Golshan, Nasser; Kliore, Arvydas

    2002-01-01

    This handbook examines the effects of the Martian environment on radio wave propagation on Mars and in the space near the planet. The environmental effects include these from the Martian atmosphere, ionosphere, global dust storms, aerosols, clouds, and geomorphologic features. Relevant Martian environmental parameters were extracted from the measurements of Mars missions during the past 30 years, especially from Mars Pathfinder and Mars Global Surveyor. The results derived from measurements and analyses have been reviewed through an extensive literature search. The updated parameters have been theoretically analyzed to study their effects on radio propagation. This handbook also provides basic information about the entire telecommunications environment on and around Mars for propagation researchers, system engineers, and link analysts. Based on these original analyses, some important recommendations have been made, including the use of the Martian ionosphere as a reflector for Mars global or trans-horizon communication between future Martian colonies, reducing dust storm scattering effects, etc. These results have extended our wave propagation knowledge to a planet other than Earth; and the tables, models, and graphics included in this handbook will benefit telecommunication system engineers and scientific researchers.

  20. Communicating radio astronomy with the public: Another point of view

    Science.gov (United States)

    Varano, S.

    2008-06-01

    Radio waves cannot be sensed directly, but they are used in daily life by almost everybody. Even so, the majority of the general public do not even know that celestial bodies emit radio waves. Presenting invisible radiation to a general audience with little or no background knowledge in physics is a difficult task. In addition, much important technology now commonplace in many other scientific fields was pioneered by radio observatories in their efforts to detect and process radio signals from the Universe. Radio astronomy outreach does not have such a well-established background as optical astronomy outreach. In order to make radio astronomy accessible to the public, it is necessary either to add more scientific detail or to find a different way of communicating. In this paper we present examples from our work at the Visitor Centre "Marcello Ceccarelli", which is part of the Medicina Radio Observatory, operated by the Institute of Radio Astronomy (IRA) in Bologna, which in turn is part of the National Institute for Astrophysics (INAF).

  1. 75 FR 20951 - Amendment of the Commission's Rules Regarding Amateur Radio Service Communications During...

    Science.gov (United States)

    2010-04-22

    ... COMMISSION 47 CFR Part 97 Amendment of the Commission's Rules Regarding Amateur Radio Service Communications...-based communications for emergency responders, experience has shown that amateur radio has played an... radio communication at its disposal to provide essential communication needs in connection with...

  2. 49 CFR 220.21 - Railroad operating rules; radio communications; recordkeeping.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Railroad operating rules; radio communications...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.21 Railroad operating rules; radio communications; recordkeeping. (a)...

  3. Radio Ranging System for Guidance of Approaching Spacecraft

    Science.gov (United States)

    Manikonda, Vikram; vanDoom, Eric

    2008-01-01

    A radio communication and ranging system has been proposed for determining the relative position and orientations of two approaching spacecraft to provide guidance for docking maneuvers. On Earth, the system could be used similarly for guiding approaching aircraft and for automated positioning of large, heavy objects. In principle, the basic idea is to (1) measure distances between radio transceivers on the two spacecraft and (2) compute the relative position and orientations from the measured distances.

  4. JPL Space Telecommunications Radio System Operating Environment

    Science.gov (United States)

    Lux, James P.; Lang, Minh; Peters, Kenneth J.; Taylor, Gregory H.; Duncan, Courtney B.; Orozco, David S.; Stern, Ryan A.; Ahten, Earl R.; Girard, Mike

    2013-01-01

    A flight-qualified implementation of a Software Defined Radio (SDR) Operating Environment for the JPL-SDR built for the CoNNeCT Project has been developed. It is compliant with the NASA Space Telecommunications Radio System (STRS) Architecture Standard, and provides the software infrastructure for STRS compliant waveform applications. This software provides a standards-compliant abstracted view of the JPL-SDR hardware platform. It uses industry standard POSIX interfaces for most functions, as well as exposing the STRS API (Application Programming In terface) required by the standard. This software includes a standardized interface for IP components instantiated within a Xilinx FPGA (Field Programmable Gate Array). The software provides a standardized abstracted interface to platform resources such as data converters, file system, etc., which can be used by STRS standards conformant waveform applications. It provides a generic SDR operating environment with a much smaller resource footprint than similar products such as SCA (Software Communications Architecture) compliant implementations, or the DoD Joint Tactical Radio Systems (JTRS).

  5. Radio frequency integrated circuit design for cognitive radio systems

    CERN Document Server

    Fahim, Amr

    2015-01-01

    This book fills a disconnect in the literature between Cognitive Radio systems and a detailed account of the circuit implementation and architectures required to implement such systems.  Throughout the book, requirements and constraints imposed by cognitive radio systems are emphasized when discussing the circuit implementation details.  In addition, this book details several novel concepts that advance state-of-the-art cognitive radio systems.  This is a valuable reference for anybody with background in analog and radio frequency (RF) integrated circuit design, needing to learn more about integrated circuits requirements and implementation for cognitive radio systems. ·         Describes in detail cognitive radio systems, as well as the circuit implementation and architectures required to implement them; ·         Serves as an excellent reference to state-of-the-art wideband transceiver design; ·         Emphasizes practical requirements and constraints imposed by cognitive radi...

  6. Multi-Objective Reinforcement Learning for Cognitive Radio-Based Satellite Communications

    Science.gov (United States)

    Ferreira, Paulo Victor R.; Paffenroth, Randy; Wyglinski, Alexander M.; Hackett, Timothy M.; Bilen, Sven G.; Reinhart, Richard C.; Mortensen, Dale J.

    2016-01-01

    Previous research on cognitive radios has addressed the performance of various machine-learning and optimization techniques for decision making of terrestrial link properties. In this paper, we present our recent investigations with respect to reinforcement learning that potentially can be employed by future cognitive radios installed onboard satellite communications systems specifically tasked with radio resource management. This work analyzes the performance of learning, reasoning, and decision making while considering multiple objectives for time-varying communications channels, as well as different cross-layer requirements. Based on the urgent demand for increased bandwidth, which is being addressed by the next generation of high-throughput satellites, the performance of cognitive radio is assessed considering links between a geostationary satellite and a fixed ground station operating at Ka-band (26 GHz). Simulation results show multiple objective performance improvements of more than 3.5 times for clear sky conditions and 6.8 times for rain conditions.

  7. A cellular-based solution for radio communications in MOUT

    NARCIS (Netherlands)

    Overduin, R.

    2005-01-01

    A short-term and potentially cost-effective solution is proposed for tactical radio communications in Military Operations in Urban Terrain (MOUT) for the Royal Netherlands Army (RNLA). Measurements and computer simulations presented show that on average, outdoor ranges in MOUT as attainable with

  8. Rainfall measurement using radio links from cellular communication networks

    NARCIS (Netherlands)

    Leijnse, H.; Uijlenhoet, R.; Stricker, J.N.M.

    2007-01-01

    We investigate the potential of radio links such as employed by commercial cellular communication companies to monitor path-averaged rainfall. We present an analysis of data collected using two 38-GHz links during eight rainfall events over a 2-month period (October¿November 2003) during mostly stra

  9. A cellular-based solution for radio communications in MOUT

    NARCIS (Netherlands)

    Overduin, R.

    2005-01-01

    A short-term and potentially cost-effective solution is proposed for tactical radio communications in Military Operations in Urban Terrain (MOUT) for the Royal Netherlands Army (RNLA). Measurements and computer simulations presented show that on average, outdoor ranges in MOUT as attainable with RNL

  10. Optimal One Bit Time Reversal For UWB Impulse Radio In Multi-User Wireless Communications

    DEFF Research Database (Denmark)

    Nguyen, Hung Tuan

    2008-01-01

    In this paper, with the purpose of further reducing the complexity of the system, while keeping its temporal and spatial focusing performance, we investigate the possibility of using optimal one bit time reversal (TR) system for impulse radio ultra wideband multi-user wireless communications...

  11. 47 CFR 90.656 - Responsibilities of base station licensees of Specialized Mobile Radio systems.

    Science.gov (United States)

    2010-10-01

    ... Specialized Mobile Radio systems. 90.656 Section 90.656 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Bands § 90.656 Responsibilities of base station licensees of Specialized Mobile Radio systems. (a) The licensees of base stations that provide Specialized Mobile Radio service on a commercial basis of the use...

  12. MicrobeWorld Radio and Communications Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Barbara Hyde

    2006-11-22

    MicrobeWorld is a 90-second feature broadcast daily on more than 90 public radio stations and available from several sources as a podcast, including www.microbeworld.org. The feature has a strong focus on the use and adapatbility of microbes as alternative sources of energy, in bioremediation, their role in climate, and especially the many benefits and scientific advances that have resulting from decoding microbial genomes. These audio features are permanantly archived on an educational outreach site, microbeworld.org, where they are linked to the National Science Education Standards. They are also being used by instructors at all levels to introduce students to the multiple roles and potential of microbes, including a pilot curriculum program for middle-school students in New York.

  13. Speech Communication Via Radio and Television.

    Science.gov (United States)

    Starlin, Glenn; Sherriffs, Ronald

    Designed to serve as a practical introduction to the functions of the broadcast media and as a guide to adjustment to demands imposed by the media on speakers, this book attempts to deal with special problems of the ordinary citizen in preparation for broadcast talks. A first part focuses on the media--changing patterns of communication,…

  14. Advanced Radio Resource Management for Multi Antenna Packet Radio Systems

    OpenAIRE

    Stanislav Nonchev; Mikko Valkama

    2010-01-01

    In this paper, we propose fairness-oriented packet scheduling (PS) schemes with power-efficientcontrol mechanism for future packet radio systems. In general, the radio resource managementfunctionality plays an important role in new OFDMA based networks. The control of the networkresource division among the users is performed by packet scheduling functionality based on maximizingcell coverage and capacity satisfying, and certain quality of service requirements. Moreover, multiantennatransmit-r...

  15. Impact of transport layer protocols on the efficiency of special purpose radio-communications

    OpenAIRE

    NEDELJKOVIC LJUBISA S.

    2014-01-01

    The efficiency of special purpose radio-communications depends on transport layer protocols. Meny factors have an impact on special purpose radio-communications efficiency, as well as TCP and UDP protocols. This paper presents the transport protocols throughput analysis in the HF and VHF radio-communications versus RTT and packet error rate probability. This paper considers a posibility of the application of TCP and UDP protocols in special purpose radio-communications. The following factors ...

  16. Executive summary. [application of laser oriented and radio frequency techniques for space communication

    Science.gov (United States)

    1973-01-01

    The scope of Technology Forecasting for Space Communications is very wide, covering virtually every technology that can directly or indirectly affect space communications. The assigned effort, however, was directed toward a series of studies which individually examined important aspects of space communications and which collectively was interrelated. The contributions of the individual tasks and their interrelationship are indicated. The total effort of the tasks was fairly evenly divided between laser oriented and radio frequency tasks. The investigations show that laser communications have a current state of the art which would allow operational systems to be implemented in the 1975 to 1980 time frame. Further, these systems, when operated over ranges in the order of synchronous ranges (42,000 km)and transmitting data rates of 10 to the 8th power 10 to the 9th power bits per second will have a smaller total weight impact on a spacecraft than do radio systems.

  17. Cognitive radio networks efficient resource allocation in cooperative sensing, cellular communications, high-speed vehicles, and smart grid

    CERN Document Server

    Jiang, Tao; Cao, Yang

    2015-01-01

    PrefaceAcknowledgmentsAbout the AuthorsIntroductionCognitive Radio-Based NetworksOpportunistic Spectrum Access NetworksCognitive Radio Networks with Cooperative SensingCognitive Radio Networks for Cellular CommunicationsCognitive Radio Networks for High-Speed VehiclesCognitive Radio Networks for a Smart GridContent and OrganizationTransmission Slot Allocation in an Opportunistic Spectrum Access NetworkSingle-User Single-Channel System ModelProbabilistic Slot Allocation SchemeOptimal Probabilistic Slot AllocationBaseline PerformanceExponential DistributionHyper-Erlang DistributionPerformance An

  18. 5G multimedia massive MIMO communications systems

    OpenAIRE

    Ge, Xiaohu; Wang, Haichao; Zi, Ran; Li, Qiang; Ni, Qiang

    2016-01-01

    In the fifth generation (5G) wireless communication systems, a majority of the traffic demands are contributed by various multimedia applications. To support the future 5G multimedia communication systems, the massive multiple-input multiple-output (MIMO) technique is recognized as a key enabler because of its high spectral efficiency. The massive antennas and radio frequency chains not only improve the implementation cost of 5G wireless communication systems but also result in an intense mut...

  19. SOCIOLINGUISTIC ASPECTS OF THE STUDY OF PECULIARITIES OF RADIO COMMUNICATION

    Directory of Open Access Journals (Sweden)

    Nataliya Pazyura

    2016-06-01

    Full Text Available Purpose. Flight safety has always been in the center of attention of scientists and practitioners in aviation. That is why in the end of the last century the ICAO assembly recognized inadequate English proficiency among flight crews and controllers as a contributing factor in aviation accidents. It also directed the ICAO’s Air Navigation Commission (ANC to strengthen the provisions for the use of English in aeronautical radiotelephony (air traffic communications in Annex 1 - Personnel Licensing and Annex 10 – Aeronautical Telecommunications. Results. The article is devoted to the study of peculiarities of communication in aviation – radio communication between an air traffic controller and pilot, which is very important for promotion of flight safety. The author pays special attention to the study of social factors influencing the choice of certain lexical units and functional styles. Methods. For our research we used scientific general methods which are main ways of studying scientific sources, and comparative-historical method for synchronic comparison of event in the same region. Discussion. The factors that explain such linguistic choice during communication have been characterized. Similar and different features of professional radio communication and usual every day communication have been revealed. Some examples are given and explained according to specific professional activity.

  20. Software Defined Radios - Architectures, Systems and Functions

    Science.gov (United States)

    Sims, Herb

    2017-01-01

    Software Defined Radio is an industry term describing a method of utilizing a minimum amount of Radio Frequency (RF)/analog electronics before digitization takes place. Upon digitization all other functions are performed in software/firmware. There are as many different types of SDRs as there are data systems. Software Defined Radio (SDR) technology has been proven in the commercial sector since the early 90's. Today's rapid advancement in mobile telephone reliability and power management capabilities exemplifies the effectiveness of the SDR technology for the modern communications market. In contrast the foundations of transponder technology presently qualified for satellite applications were developed during the early space program of the 1960's. SDR technology offers potential to revolutionize satellite transponder technology by increasing science data through-put capability by at least an order of magnitude. While the SDR is adaptive in nature and is "One-size-fits-all" by design, conventional transponders are built to a specific platform and must be redesigned for every new bus. The SDR uses a minimum amount of analog/Radio Frequency components to up/down-convert the RF signal to/from a digital format. Once analog data is digitized, all processing is performed using hardware logic. Typical SDR processes include; filtering, modulation, up/down converting and demodulation. This presentation will show how the emerging SDR market has leveraged the existing commercial sector to provide a path to a radiation tolerant SDR transponder. These innovations will reduce the cost of transceivers, a decrease in power requirements and a commensurate reduction in volume. A second pay-off is the increased flexibility of the SDR by allowing the same hardware to implement multiple transponder types by altering hardware logic - no change of analog hardware is required - all of which can be ultimately accomplished in orbit. This in turn would provide high capability and low cost

  1. Implementation of wireless communication based on Software Defined Radio

    OpenAIRE

    Zhang, Lei

    2013-01-01

    In current communication systems, there are many new challenges like various competitive standards, the scarcity of frequency resource, etc., especially the development of personal wireless communication systems result the new system update faster than ever before, the conventional hardware-based wireless communication system is difficult to adapt to this situation. The emergence of SDR enabled the third revolution of wireless communication which from hardware to software and build a flexible...

  2. Space Telecommunications Radio System (STRS) Architecture. Part 1; Tutorial - Overview

    Science.gov (United States)

    Handler, Louis M.; Briones, Janette C.; Mortensen, Dale J.; Reinhart, Richard C.

    2012-01-01

    Space Telecommunications Radio System (STRS) Architecture Standard provides a NASA standard for software-defined radio. STRS is being demonstrated in the Space Communications and Navigation (SCaN) Testbed formerly known as Communications, Navigation and Networking Configurable Testbed (CoNNeCT). Ground station radios communicating the SCaN testbed are also being written to comply with the STRS architecture. The STRS Architecture Tutorial Overview presents a general introduction to the STRS architecture standard developed at the NASA Glenn Research Center (GRC), addresses frequently asked questions, and clarifies methods of implementing the standard. The STRS architecture should be used as a base for many of NASA s future telecommunications technologies. The presentation will provide a basic understanding of STRS.

  3. Modeling radio communication blackout and blackout mitigation in hypersonic vehicles

    CERN Document Server

    Kundrapu, Madhusudhan; Beckwith, Kristian; Stoltz, Peter; Shashurin, Alexey; Keidar, Michael

    2014-01-01

    A procedure for the modeling and analysis of radio communication blackout of hypersonic vehicles is presented. A weakly ionized plasma generated around the surface of a hypersonic reentry vehicle traveling at Mach 23 was simulated using full Navier-Stokes equations in multi-species single fluid form. A seven species air chemistry model is used to compute the individual species densities in air including ionization - plasma densities are compared with experiment. The electromagnetic wave's interaction with the plasma layer is modeled using multi-fluid equations for fluid transport and full Maxwell's equations for the electromagnetic fields. The multi-fluid solver is verified for a whistler wave propagating through a slab. First principles radio communication blackout over a hypersonic vehicle is demonstrated along with a simple blackout mitigation scheme using a magnetic window.

  4. Keeping Communications Flowing During Large-scale Disasters: Leveraging Amateur Radio Innovations for Disaster Medicine.

    Science.gov (United States)

    Cid, Victor H; Mitz, Andrew R; Arnesen, Stacey J

    2017-09-25

    Medical facilities may struggle to maintain effective communications during a major disaster. Natural and man-made disasters threaten connectivity by degrading or crippling Internet, cellular/mobile, and landline telephone services across wide areas. Communications among staff, between facilities, and to resources outside the disaster area may be lost for an extended time. A prototype communications system created by the National Library of Medicine (NLM) provides basic communication services that ensure essential connectivity in the face of widespread infrastructure loss. It leverages amateur radio to provide resilient email service to local users, enabling them to reach intact communications networks outside the disaster zone. Because amateur radio is inexpensive, always available, and sufficiently independent of terrestrial telecommunications infrastructure, it has often augmented telecommunications capabilities of medical facilities. NLM's solution is unique in that it provides end-user to end-user direct email communications, without requiring the intervention of a radio operator in the handling of the messages. Medical staff can exchange email among themselves and with others outside the communications blackout zone. The technology is portable, is deployable on short notice, and can be powered in a variety of ways to adapt to the circumstances of each crisis. (Disaster Med Public Health Preparedness. 2017; page 1 of 8).

  5. 25 CFR 169.26 - Telephone and telegraph lines; radio, television, and other communications facilities.

    Science.gov (United States)

    2010-04-01

    ...; radio, television, and other communications facilities. (a) The Act of February 15, 1901 (31 Stat. 790... communication purposes, and for radio, television, and other forms of communication transmitting, relay, and... relative positions. (e) Rights-of-way for poles and lines for communication purposes, and for...

  6. Interference Cancellation System Design Using GNU Radio

    Science.gov (United States)

    2015-12-01

    ARL-TR-7546 ● DEC 2015 US Army Research Laboratory Interference Cancellation System Design Using GNU Radio by Jan Paolo...Interference Cancellation System Design Using GNU Radio by Jan Paolo Acosta Sensors and Electron Devices Directorate, ARL...Design Using GNU Radio 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Jan Paolo Acosta 5d. PROJECT NUMBER

  7. An adaptive software defined radio design based on a standard space telecommunication radio system API

    Science.gov (United States)

    Xiong, Wenhao; Tian, Xin; Chen, Genshe; Pham, Khanh; Blasch, Erik

    2017-05-01

    Software defined radio (SDR) has become a popular tool for the implementation and testing for communications performance. The advantage of the SDR approach includes: a re-configurable design, adaptive response to changing conditions, efficient development, and highly versatile implementation. In order to understand the benefits of SDR, the space telecommunication radio system (STRS) was proposed by NASA Glenn research center (GRC) along with the standard application program interface (API) structure. Each component of the system uses a well-defined API to communicate with other components. The benefit of standard API is to relax the platform limitation of each component for addition options. For example, the waveform generating process can support a field programmable gate array (FPGA), personal computer (PC), or an embedded system. As long as the API defines the requirements, the generated waveform selection will work with the complete system. In this paper, we demonstrate the design and development of adaptive SDR following the STRS and standard API protocol. We introduce step by step the SDR testbed system including the controlling graphic user interface (GUI), database, GNU radio hardware control, and universal software radio peripheral (USRP) tranceiving front end. In addition, a performance evaluation in shown on the effectiveness of the SDR approach for space telecommunication.

  8. Radio access selection in multi-radio access systems

    NARCIS (Netherlands)

    Jorgušeski, L.; Litjens, R.; Zhiyi, C.; Nikookar, H.

    2007-01-01

    Future wireless access systems will be characterized by their heterogeneity from technological point of view. It is envisaged that in certain areas end-users will have a choice between various radio accesses (RAs) such as e.g. classical cellular networks (GSM, UMTS, WiMAX, etc), WLAN hot-spots, or o

  9. Analysis of Unmmanned Air Vehicles Communication Systems

    Directory of Open Access Journals (Sweden)

    Darius Rudinskas

    2011-04-01

    Full Text Available The analyzed questions of information security transferable by the radio connection link are presented in this article. This safety it is especially important for design of unmanned air vehicles (UAV and for other remote control vehicles. Also questions about UAV communication systems structure, security treats of radio connection system, possible menaces for secure information transferring, security and integrity are discussed in our presentation. Article in Lithuanian

  10. Rapid Prototyping by 3D Printing for Advanced Radio Communications at 80 GHz and Above

    DEFF Research Database (Denmark)

    Salazar, Adrian Ruiz; Rommel, Simon; Anufriyev, Eldar

    2016-01-01

    This paper discusses the potential of 3D printing for the manufacturing of spiral phase plates for the generation of radio vortex beams for advanced radio communications. The design and prototyping of a number of phase plates for communications at 80GHz with radio vortex beams is discussed...

  11. Next generation wireless communications using radio over fiber

    CERN Document Server

    Gomes, Nathan J; Gameiro, Atilio

    2012-01-01

    Taking a coherent and logical approach, this book describes the potential use of co-ordinated multipoint systems supported by radio over fiber. It covers an impressive breadth of topics, ranging from components, subsystem and system architecture, to network management and business perspectives. The authors show the importance of radio over fiber in eliminating or mitigating against the current, perceived barriers to the use of co-ordinated multipoint, and the drivers for standardisation activities in future mobile/wireless systems over the next few years. The book brings together the

  12. Modeling and simulating of wireless communication system with GNU Radio and USRP%基于GNU Radio和USRP的无线通信系统建模仿真

    Institute of Scientific and Technical Information of China (English)

    杨宏; 孔耀晖; 茹晨光; 李珂; 潘赟

    2013-01-01

    To achieve rapid and accurate modeling and simulation for wireless communication system in complex wireless transmission environment,a software radio system consisting of GNU Radio and USRP is applied in this paper as a new model-ing and simulation method for wireless communication system. Its software characteristics and hardware framework are analyzed. A comparison experiment on link model bit error rate of MPSK modulation system working in the real channel and simulation channel was performed. A prototype of wireless video transmission system was realized based on the link module with the real wireless channel. Analysis and experiment results show that the new modeling and simulation method with software radio system has superiorities in rapid prototype implementation and capacity to bring the real wireless channel into system model to achieve more accurate simulation and analysis result. This method is applicable to the research and design of wireless communication sys-tems with customized requirements of complex transmission environment.%针对无线通信环境的复杂特性,为了实现无线通信系统快速准确的建模仿真,应用GNU Radio和USRP组成的软件无线电系统作为新的建模仿真方法。介绍并分析该方法的软件特性和硬件架构,进行MPSK调制系统在仿真信道和实际信道下链路模型的误码率对比实验,并在包含实际无线信道的链路模型基础上,设计并实现了一套无线视频流传输原型系统。分析和实验结果表明,新方法能够快速实现无线通信系统原型,将实际无线信道纳入系统模型中,从而获得更准确的仿真和分析结果。该方法适用于对通信协议标准及系统有定制化需求、针对传输环境复杂的无线通信系统研究开发。

  13. Digital Audio Radio Broadcast Systems Laboratory Testing Nearly Complete

    Science.gov (United States)

    2005-01-01

    Radio history continues to be made at the NASA Lewis Research Center with the completion of phase one of the digital audio radio (DAR) testing conducted by the Consumer Electronics Group of the Electronic Industries Association. This satellite, satellite/terrestrial, and terrestrial digital technology will open up new audio broadcasting opportunities both domestically and worldwide. It will significantly improve the current quality of amplitude-modulated/frequency-modulated (AM/FM) radio with a new digitally modulated radio signal and will introduce true compact-disc-quality (CD-quality) sound for the first time. Lewis is hosting the laboratory testing of seven proposed digital audio radio systems and modes. Two of the proposed systems operate in two modes each, making a total of nine systems being tested. The nine systems are divided into the following types of transmission: in-band on-channel (IBOC), in-band adjacent-channel (IBAC), and new bands. The laboratory testing was conducted by the Consumer Electronics Group of the Electronic Industries Association. Subjective assessments of the audio recordings for each of the nine systems was conducted by the Communications Research Center in Ottawa, Canada, under contract to the Electronic Industries Association. The Communications Research Center has the only CCIR-qualified (Consultative Committee for International Radio) audio testing facility in North America. The main goals of the U.S. testing process are to (1) provide technical data to the Federal Communication Commission (FCC) so that it can establish a standard for digital audio receivers and transmitters and (2) provide the receiver and transmitter industries with the proper standards upon which to build their equipment. In addition, the data will be forwarded to the International Telecommunications Union to help in the establishment of international standards for digital audio receivers and transmitters, thus allowing U.S. manufacturers to compete in the

  14. Transceiver and system design for digital communications

    CERN Document Server

    Bullock, Scott R

    2014-01-01

    This is the fourth edition of this successful professional reference book on transceiver design, the device that both sends and receives signals, and its place within the wireless communication system. It gives engineers and others a good intuitive understanding of wireless systems and spread spectrum. New topics covered include cognitive radio, systems, networks, and commercial communications. In addition, many items have been extensively updated to improve the flow of the book and enhance comprehension.

  15. Advanced Radio Resource Management for Multi Antenna Packet Radio Systems

    CERN Document Server

    Nonchev, Stanislav; 10.5121/ijwmn.2010.2201

    2010-01-01

    In this paper, we propose fairness-oriented packet scheduling (PS) schemes with power-efficient control mechanism for future packet radio systems. In general, the radio resource management functionality plays an important role in new OFDMA based networks. The control of the network resource division among the users is performed by packet scheduling functionality based on maximizing cell coverage and capacity satisfying, and certain quality of service requirements. Moreover, multiantenna transmit-receive schemes provide additional flexibility to packet scheduler functionality. In order to mitigate inter-cell and co-channel interference problems in OFDMA cellular networks soft frequency reuse with different power masks patterns is used. Stemming from the earlier enhanced proportional fair scheduler studies for single-input multiple-output (SIMO) and multiple-input multipleoutput (MIMO) systems, we extend the development of efficient packet scheduling algorithms by adding transmit power considerations in the ove...

  16. 49 CFR 220.29 - Statement of letters and numbers in radio communications.

    Science.gov (United States)

    2010-10-01

    ...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.29 Statement of letters and numbers in radio communications. (a) If necessary for... 49 Transportation 4 2010-10-01 2010-10-01 false Statement of letters and numbers in...

  17. Coordination procedure for radio relay and communication satellite services

    Science.gov (United States)

    Eckerman, J.

    1973-01-01

    A global rain rate statistic model is used to link microwave propagation statistics to measurable rain statistics in order to develop international telecommunication site criteria for radio relay and communication satellite services that minimize interference between receivers and transmitters. This rain coordination procedure utilizes a rain storm cell size, a statistical description of the rainfall rate within the cell valid for most of the earth's surface, approximations between Raleigh scatter and constancy of precipitation with altitude, and an analytic relation between radar reflectivity and rain rate.

  18. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project - Gen-4 and Gen-5 Radio Plans

    Science.gov (United States)

    Griner, James H.

    2014-01-01

    NASA's UAS Integration in the NAS project, has partnered with Rockwell Collins to develop a concept Control and Non-Payload Communication (CNPC) system prototype radio, operating on recently allocated UAS frequency spectrum bands. This prototype radio is being used to validate initial proposed performance requirements for UAS control communications. This presentation will give an overview of the current plans for the prototype radio development.

  19. Radiation effects on communication performance of radio frequency identification tags.

    Science.gov (United States)

    Mori, Kazuyuki; Meng, Zhaowu; Kikuchi, Hirosumi; Kataoka, Yasuhide; Nakazato, Kazuhisa; Deji, Shizuhiko; Ito, Shigeki; Saze, Takuya; Hirota, Masahiro; Nishizawa, Kunihide

    2010-11-01

    Radioactive materials (sources) are managed by bookkeeping and stocktaking. The radiation protection section staffs should check the sources manually. Annual effective dose concerning stocktaking of them are estimated at some mSv concerning fingers. A radio frequency identification (RFID) tag's absorbed dose is estimated at some dozen Gy. RFID for stocktaking automatically was devised. Radiation effects on the communication performance of RFID tags were investigated by using response times and read ranges as indices. The RFID system was composed of a computer, a detector, and transponders (tag) consisting of an integrated circuit chip and an antenna. The tag is joined to the source for identification. The tags were irradiated at doses between 5 and 5,000 Gy by an x-ray irradiator. The response times and the read ranges were tracked from 40 to 23,200 min after irradiation. Relative read ranges fluctuated between 0.9 and 1.1 in the dose region less than 2,000 Gy, but fluctuated greatly in the dose region beyond 2,000 Gy. Malfunctioning tags appeared from 3,000 Gy, and all tags malfunctioned in the dose region over 4,500 Gy. The threshold dose leading to malfunction was determined to be 2,100 Gy. Time variation of relative read ranges was classified into four patterns. The pattern shifted from pattern 1 to 4 when the dose was increased. The relative read ranges lengthened in pattern 1. The relative read rages were approximately 1.0 in pattern 2. The read ranges tentatively shortened, then recovered in pattern 3. The tags malfunctioned in pattern 4. Once the tags malfunctioned, they never recovered their performance. Radiation enhances or deteriorates communication performance depending on dosage. Tags can spontaneously recover from radiation deterioration. The time variation of the read ranges can be illustrated by enhancement, deterioration, and recovery. The mechanism of four patterns is explained based on the variation of the frequency harmonization strength and

  20. Interpole Communication in Radio Pulsars and the Resulting Theoretical Challenges

    Science.gov (United States)

    Weltevrede, P.; Wright, G.; Johnston, S.

    2012-12-01

    Here we discuss some recent, and less recent, radio observations that demonstrate an intimate link between the emission generated by opposite magnetic poles of neutron stars. More specifically, there are examples of pulsars which show quasi-periodic brightening of the emission generated by both poles with a time delay which remains fixed on a timescale of at least years. This implies that the opposite magnetic poles do not operate independently of each other, leading to the question about the nature of the communication channel. In the case of PSR B1055-52 this time delay is very large, corresponding to a light travel distance of many times the light cylinder radius. A number of physical models are explored and significant objections can be made to each model. So the communication channel between the magnetic poles of pulsars remains elusive, although its understanding could prove crucial to understanding the large-scale structure of magnetospheres.

  1. 47 CFR 90.465 - Control of systems of communication.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Control of systems of communication. 90.465... SERVICES PRIVATE LAND MOBILE RADIO SERVICES Transmitter Control § 90.465 Control of systems of communication. (a) Depending on design considerations, control of a system of communication may be exercised in...

  2. Optimizing power efficiency in radio-over-fiber systems

    DEFF Research Database (Denmark)

    Koonen, A. M. J.; Popov, M.; Wessing, Henrik

    2013-01-01

    Fiber-fed radio pico-cells topologies can reduce the overall power consumption of wireless communication networks. Joint optimization of fiber and radio network parts yields an optimum number of pico-cells which minimizes power consumption.......Fiber-fed radio pico-cells topologies can reduce the overall power consumption of wireless communication networks. Joint optimization of fiber and radio network parts yields an optimum number of pico-cells which minimizes power consumption....

  3. Impulse Radio Ultra-Wideband Communication Over Free-Space Optical Links

    CERN Document Server

    Davaslioglu, Kemal

    2013-01-01

    A composite impulse radio ultra-wideband (IR-UWB) communication system is presented. The proposed system model aims to transmit UWB pulses over several kilometers through free-space optical (FSO) links and depending on the link design, the electrical estimates of the FSO system can be directly used or distributed to end-user through radio-frequency (RF) links over short ranges. However, inhomogeneities on the FSO transmission path cause random fluctuations in the received signal intensity and these effects induced by atmospheric turbulence closely effect the system performance. Several distinct probability distributions based on experimental measurements are used to characterize FSO channels and using these probabilistic models, detection error probability analysis of the proposed system for different link designs are carried out under weak, moderate and strong turbulence conditions. The results of the analysis show that depending on the atmospheric conditions, system performance of the composite link can hav...

  4. Performance of transmit-reference radio system in frequency-selective fading channels

    NARCIS (Netherlands)

    Wang, Jing; Haartsen, J.C.

    2005-01-01

    Noise-based Transmit-Reference (TR) radio system is a simple and practical candidate for ultra-wideband (UWB) communication applications. This paper evaluates the performance of the Transmit-Reference radio system in a frequency-selective fading channel by theoretical analysis and computer

  5. Communications satellite system for Africa

    Science.gov (United States)

    Kriegl, W.; Laufenberg, W.

    1980-09-01

    Earlier established requirement estimations were improved upon by contacting African administrations and organizations. An enormous demand is shown to exist for telephony and teletype services in rural areas. It is shown that educational television broadcasting should be realized in the current African transport and communications decade (1978-1987). Radio broadcasting is proposed in order to overcome illiteracy and to improve educational levels. The technical and commercial feasibility of the system is provided by computer simulations which demonstrate how the required objectives can be fulfilled in conjunction with ground networks.

  6. Communication System and Method

    Science.gov (United States)

    Sanders, Adam M. (Inventor); Strawser, Philip A. (Inventor)

    2014-01-01

    A communication system for communicating over high-latency, low bandwidth networks includes a communications processor configured to receive a collection of data from a local system, and a transceiver in communication with the communications processor. The transceiver is configured to transmit and receive data over a network according to a plurality of communication parameters. The communications processor is configured to divide the collection of data into a plurality of data streams; assign a priority level to each of the respective data streams, where the priority level reflects the criticality of the respective data stream; and modify a communication parameter of at least one of the plurality of data streams according to the priority of the at least one data stream.

  7. China's Largest Radio Antenna System

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ After three-and-half-year efforts, the National Astronomical Observatories at CAS (NAOC) has constructed two arrays of radio antennae: a 50m antenna at Miyun Station in Beijing and a 40m antenna in Kunming, capital of southwest China's Yunnan Province.

  8. Testing Gravitation in the Solar System with Radio Science experiments

    CERN Document Server

    Hees, A; Lamine, B; Jaekel, M T; Poncin-Lafitte, C Le; Lainey, V; Dehant, V

    2011-01-01

    The laws of gravitation have been tested for a long time with steadily improving precision, leading at some moment of time to paradigmatic evolutions. Pursuing this continual effort is of great importance for science. In this communication, we focus on Solar System tests of gravity and more precisely on possible tests that can be performed with radio science observations (Range and Doppler). After briefly reviewing the current tests of gravitation at Solar System scales, we give motivations to continue such experiments. In order to obtain signature and estimate the amplitude of anomalous signals that could show up in radio science observables because of modified gravitational laws, we developed a new software that simulates Range/Doppler signals. We present this new tool that simulates radio science observables directly from the space-time metric. We apply this tool to the Cassini mission during its cruise from Jupiter to Saturn and derive constraints on the parameters entering alternative theories of gravity...

  9. Communications and Intelligent Systems Division Overview

    Science.gov (United States)

    Emerson, Dawn

    2017-01-01

    Provides expertise, and plans, conducts and directs research and engineering development in the competency fields of advanced communications and intelligent systems technologies for applications in current and future aeronautics and space systems.Advances communication systems engineering, development and analysis needed for Glenn Research Center's leadership in communications and intelligent systems technology. Focus areas include advanced high frequency devices, components, and antennas; optical communications, health monitoring and instrumentation; digital signal processing for communications and navigation, and cognitive radios; network architectures, protocols, standards and network-based applications; intelligent controls, dynamics and diagnostics; and smart micro- and nano-sensors and harsh environment electronics. Research and discipline engineering allow for the creation of innovative concepts and designs for aerospace communication systems with reduced size and weight, increased functionality and intelligence. Performs proof-of-concept studies and analyses to assess the impact of the new technologies.

  10. Resource Dependent Radio Allocation For Battlefield Communications - A Data Model Approach

    Directory of Open Access Journals (Sweden)

    Gregor Thomeczek

    2014-10-01

    Full Text Available Network Enabled Capability (NEC and the Land Open Systems Architecture (LOSA are novel approaches to enable interoperability between a heterogeneous collection of assets in the battlefield. These paradigms utilise an underlying network for cooperation between deployed battlefield equipment. NEC and LOSA have great potential to transform military communications and enhance integrated survivability as well as situational awareness, but the Achilles’ heel of NEC and LOSA is the wireless spectrum over which they must communicate. A noisy and dynamic battlefield wireless spectrum as well as an array of heterogeneous wireless communications equipment handling multiple types of data with different Quality of Service (QoS requirements requires a system which manages and allocates these communication resources effectively. This paper presents the High Availability Wireless Communications (HAWC system, a hardware agnostic communications controller middleware to manage any combination of existing and future multiband wireless resources. The system utilises a vehicle’s data model to gather information about available radio resources and enable LOSA by meeting communications data requirements and delivering appropriate QoS to the appropriate traffic in a fleet of vehicles. The functionality of the system is verified by using behavioural simulation on a virtual battlefield.

  11. STS-37 Pilot Cameron uses SAREX to communicate amateur radio operators

    Science.gov (United States)

    1991-01-01

    STS-37 Pilot Kenneth D. Cameron, wearing Shuttle Amateur Radio Experiment (SAREX) headset (HDST), communicates with amateur radio operators and students while on aft flight deck aboard Atlantis, Orbiter Vehicle (OV) 104. SAREX provided radio transmissions between ground based amateur radio operators around the world and Cameron (call sign KB5AWP) and the other crewmembers, all of whom are licensed amateur radio operators. SAREX enabled students from all over the United States to have a chance to communicate with an astronaut in space. The cloud-covered surface of the Earth is visible above Cameron framed in the overhead window W8.

  12. Control and Non-Payload Communications Generation 1 Prototype Radio Flight Test Report

    Science.gov (United States)

    Shalkhauser, Kurt A.; Young, Daniel P.; Bretmersky, Steven C.; Ishac, Joseph A.; Walker, Steven H.; Griner, James H.; Kachmar, Brian A.

    2014-01-01

    Unmanned aircraft (UA) represent a new capability that will provide a variety of services in the Government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized because of the lack of a common understanding of what is required to safely operate Unmanned Aircraft Systems in the National Airspace System (UAS in the NAS). The desire and ability to fly UA is of increasing urgency. The application of UA to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UA to the NAS. Existing Federal Aviation Regulations, procedures, and technologies do not allow routine UA access to the NAS. Access to the NAS is hampered by challenges such as the lack of an onboard pilot to see and avoid other aircraft; the ability of a single pilot or operator to control multiple UA; the reliance on command and control (C2) links; the altitudes, speeds, and duration at which the aircraft fly; and the wide variation in UA size and performance. NASA is working with other Government agencies to provide solutions that reduce technical barriers and make access to the NAS routine. This goal will be accomplished through system-level integration of key concepts, technologies, or procedures and through demonstrations of these integrated capabilities in an operationally relevant environment. This project provides an opportunity to transition the acquired empirical data and knowledge to the Federal Aviation Administration and other stakeholders to help them define the requirements for routine UA access to the NAS.Radio communications channels for UA are currently managed through exceptions and use either Department of Defense frequencies for line-of-sight (LOS) and satellite-based communications links, low-power LOS links in amateur bands, or unlicensed Industrial/Scientific/Medical (ISM) frequencies. None of these frequency bands are designated for safety and

  13. Communications, Navigation, and Timing Constraints for the Solar Imaging Radio Array (SIRA)

    Science.gov (United States)

    Lemaster, E. A.; Byler, E. A.; Aschwanden, M. J.

    2003-12-01

    The Solar Imaging Radio Array (SIRA) is a proposed NASA mission to measure solar radio emissions in the 30kHz to 30MHz region of the electromagnetic spectrum. The baseline design consists of 16 separated spacecraft in an irregular pattern several kilometers across. Each spacecraft is equipped with a pair of crossed dipole antennas that together form a 16-element radio interferometer for Fourier-type image reconstruction (120 baselines in the UV-plane). The required close coordination between this formation of spacecraft places many unique constraints on the SIRA communications, navigation, control, and timing architectures. Current specifications call for knowledge of the relative locations of the spacecraft to approximately meter-level accuracy in order to maintain primary instrument resolution. Knowledge of the relative timing differences between the clocks on the spacecraft must likewise be maintained to tens of nanoseconds or better. This in turn sets a minimum bound on the regularity of communications updates between spacecraft. Although the actual positions of the spacecraft are not tightly constrained, enough control authority and system autonomy must be present to keep the spacecraft from colliding due to orbital perturbations. Each of these constraints has an important effect on the design of the architecture for the entire array. This paper examines the engineering requirements and design tradeoffs for the communications, navigation, and timing architectures for SIRA. Topics include the choice of navigation sensor, communications methodology and modulation schemes, and clock type to meet the overall system performance goals while overcoming issues such as communications dynamic range, bandwidth limitations, power constraints, available antenna beam patterns, and processing limitations. In addition, this paper discusses how the projected use of smaller spacecraft buses with their corresponding payload and cost limits has important consequences for the

  14. Communications Systems for Mobile Robotics

    Energy Technology Data Exchange (ETDEWEB)

    Futterman, J A; Pao, H

    2003-12-08

    Performance Confirmation is the activity by which the Yucca Mountain Project confirms that the engineered and natural containment barriers of this national nuclear waste repository are performing as predicted, so that an eventual decision to close the repository can be made. This activity involves systems that must be inspected and, in some cases, serviced by mobile robots. This paper discusses systems for underground mobile robot communications, including requirements, environments, options, issues, and down-select criteria. We reviewed a variety of systems, including Slotted Waveguide, Powerline Carrier, Leaky Feeder, Photonic Bandgap Fiber, Free-Space Optics, Millimeter Waves, Terahertz Systems, and RF Systems (including IEEE 802.11 a,b, and g, and Ultra-Wideband radio).

  15. Full Duplex Wireless Communications for Cognitive Radio Networks

    CERN Document Server

    Cheng, Wenchi; Zhang, Hailin

    2011-01-01

    As a key in cognitive radio networks (CRNs), dynamic spectrum access needs to be carefully designed to minimize the interference and delay to the \\emph{primary} (licensed) users. One of the main challenges in dynamic spectrum access is to determine when the \\emph{secondary} (unlicensed) users can use the spectrum. In particular, when the secondary user is using the spectrum, if the primary user becomes active to use the spectrum, it is usually hard for the secondary user to detect the primary user instantaneously, thus causing unexpected interference and delay to primary users. The secondary user cannot detect the presence of primary users instantaneously because the secondary user is unable to detect the spectrum at the same time while it is transmitting. To solve this problem, we propose the full duplex wireless communications scheme for CRNs. In particular, we employ the Antennas Cancellation (AC), the RF Interference Cancellation (RIC), and the Digital Interference Cancellation (DIC) techniques for second...

  16. Waveform Developer's Guide for the Integrated Power, Avionics, and Software (iPAS) Space Telecommunications Radio System (STRS) Radio

    Science.gov (United States)

    Shalkhauser, Mary Jo W.; Roche, Rigoberto

    2017-01-01

    The Space Telecommunications Radio System (STRS) provides a common, consistent framework for software defined radios (SDRs) to abstract the application software from the radio platform hardware. The STRS standard aims to reduce the cost and risk of using complex, configurable and reprogrammable radio systems across NASA missions. To promote the use of the STRS architecture for future NASA advanced exploration missions, NASA Glenn Research Center (GRC) developed an STRS-compliant SDR on a radio platform used by the Advance Exploration System program at the Johnson Space Center (JSC) in their Integrated Power, Avionics, and Software (iPAS) laboratory. The iPAS STRS Radio was implemented on the Reconfigurable, Intelligently-Adaptive Communication System (RIACS) platform, currently being used for radio development at JSC. The platform consists of a Xilinx(Trademark) ML605 Virtex(Trademark)-6 FPGA board, an Analog Devices FMCOMMS1-EBZ RF transceiver board, and an Embedded PC (Axiomtek(Trademark) eBox 620-110-FL) running the Ubuntu 12.4 operating system. The result of this development is a very low cost STRS compliant platform that can be used for waveform developments for multiple applications. The purpose of this document is to describe how to develop a new waveform using the RIACS platform and the Very High Speed Integrated Circuits (VHSIC) Hardware Description Language (VHDL) FPGA wrapper code and the STRS implementation on the Axiomtek processor.

  17. Underwater Multi-Node Radio Communication Solutions for Planetary Exploration

    Science.gov (United States)

    Kawar, Zaid Fares Yousef; Haddad, Sanad Atef Sari; Mestariheh, Feras R. M.; Jonsson, Lars Jonas

    2015-01-01

    The exploration of the presumably life harboring subsurface ocean of Europa will provide scientists with extensive new knowledge in the search for extraterrestrial life. A highly miniaturized payload is required to penetrate a narrow passage through the thick ice crust covering Europa's surface. Underwater wireless communications may be the most viable means of communication for such exploratory missions, accounting for size and weight restrictions. This presents a challenge to achieve satisfactory data rates and a range that permits autonomous underwater vehicles (AUVs) to communicate within their region of operation, as well as with a surface lander or orbiter. This work presents thorough prototype experimentation on an underwater communication system established between several nodes using RF signals. During an eight-week internship experience at NASA's Ames Research Center in September-October 2014, our team developed a Europa exploration mission concept, built representative hardware, and carried out tests to assess the feasibility of key aspects of the concept. Experiments demonstrating the viability of RF communication underwater comprised inspecting the effect of depth and horizontal distance on signal strength as well as the optimum positioning of antennas. To test the system's performance, two submersibles were designed and built. A commercially available remotely operated vehicle (ROV) was also modified and used as a main communication node. The two submersibles were wirelessly connected and accommodated sensors capable of characterizing water properties and equipped with 2.4 GHz, 1 mW transceivers to communicate the measured data. The communication procedure is that the main communication node requests the collected data from the two submersibles when in range and receives it instantly through RF. This work models what may take place during an actual mission to Europa. The developed mission concept involved a hybrid communication system consisting of

  18. High-Sensitivity Phased Arrays for Radio Astronomy and Satellite Communications

    Science.gov (United States)

    Diao, Junming

    Radio astronomy is used to study stars, galaxies, black holes and gas clouds radiation at radio frequencies. Detecting extremely weak signals from deep space radio sources requires high sensitive feed system associated with large dish antennas. The key figure of merit is survey speed, or the time required to map a region of the sky to a given source flux density. Survey speed is proportional to the frequency bandwidth, the field of view or observable region of the sky, and the squared sensitivity, where sensitivity is related to reflector aperture efficiency and system noise temperature. Compared to the traditional single feed, phased array feeds with significantly expanded field of view are considered as the next generation feed for radio telescope. This dissertation outlines the design, analysis and measurement of high sensitivity L-band and mm-wave phased array feeds for the 100-meter Green Bank Telescope. Theoretical works for radio astronomy includes design guideline for high sensitivity phased array feed, fundamental frequency bandwidth limit, array antenna loss influenced by mutual coupling and beamformer coefficients and possibility of superdirectivity for radio telescopes and other antennas. These study are helpful to understand and guide the design of a phased array feed system. In the absence of dish antennas, sparse phased arrays with aperiodic structure have been developed for satellite communications. A compromise between the peak side lobe level, array element density, directivity and design complexity is studied. We have found that the array peak side lobe level can be reduced by enhancing the array element direction at the main lobe direction, increasing the array element density and enlarging the array size. A Poynting streamline approach develops to understand the properties of a receiving antenna and the mutual coupling effects between array elements. This method has been successfully used to generate effective area shape for many types of

  19. 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

  20. Radio communication for motor sports; Motor sports ni okeru musen tsushin

    Energy Technology Data Exchange (ETDEWEB)

    Ota, K. [Kenwood Corp., Tokyo (Japan)

    2000-02-01

    This paper describes general radio communication, and radio telephone and data communication for motor sports. The radio communication for racing cars is largely disturbed by car noises and peripheral noises. The adverse effect of noises caused by on-board computer on communication, and that of radio waves on a computer are unavoidable. The radio communication is also disturbed by various radio devices in a racing circuit. As disturbance measures, change of radio frequency and filtering are necessary. For the radio telephone communication between a driver and a manager or a manager and team staffs, a close-talking microphone or a microphone with a noise canceler are used to pick up proper voices from strong roaring. However, although the frequency band of engine noises is nearly equal to that of human voices, separation of voices is extremely difficult. The car data during racing are transmitted rapidly to a pit by microwave communication, and used for the planning of a race strategy in a pit. (NEDO)

  1. Advanced quantum communication systems

    Science.gov (United States)

    Jeffrey, Evan Robert

    Quantum communication provides several examples of communication protocols which cannot be implemented securely using only classical communication. Currently, the most widely known of these is quantum cryptography, which allows secure key exchange between parties sharing a quantum channel subject to an eavesdropper. This thesis explores and extends the realm of quantum communication. Two new quantum communication protocols are described. The first is a new form of quantum cryptography---relativistic quantum cryptography---which increases communication efficiency by exploiting a relativistic bound on the power of an eavesdropper, in addition to the usual quantum mechanical restrictions intrinsic to quantum cryptography. By doing so, we have observed over 170% improvement in communication efficiency over a similar protocol not utilizing relativity. A second protocol, Quantum Orienteering, allows two cooperating parties to communicate a specific direction in space. This application shows the possibility of using joint measurements, or projections onto an entangled state, in order to extract the maximum useful information from quantum bits. For two-qubit communication, the maximal fidelity of communication using only separable operations is 73.6%, while joint measurements can improve the efficiency to 78.9%. In addition to implementing these protocols, we have improved several resources for quantum communication and quantum computing. Specifically, we have developed improved sources of polarization-entangled photons, a low-loss quantum memory for polarization qubits, and a quantum random number generator. These tools may be applied to a wide variety of future quantum and classical information systems.

  2. Power Electronics System Communications

    OpenAIRE

    Milosavljevic, Ivana

    1999-01-01

    This work investigates communication issues in high-frequency power converters. A novel control communication network (Power Electronics System Network or PES Net) is proposed for modular, medium and high-power, converters. The network protocol, hardware and software are designed and implemented. The PES Net runs at 125 Mb/s over plastic optical fiber allowing converter switching frequencies in excess of 100 kHz. Communication control is implemented in a fie...

  3. A review of radio channel models for body centric communications.

    Science.gov (United States)

    Cotton, Simon L; D'Errico, Raffaele; Oestges, Claude

    2014-06-01

    The human body is an extremely challenging environment for the operation of wireless communications systems, not least because of the complex antenna-body electromagnetic interaction effects which can occur. This is further compounded by the impact of movement and the propagation characteristics of the local environment which all have an effect upon body centric communications channels. As the successful design of body area networks (BANs) and other types of body centric system is inextricably linked to a thorough understanding of these factors, the aim of this paper is to conduct a survey of the current state of the art in relation to propagation and channel models primarily for BANs but also considering other types of body centric communications. We initially discuss some of the standardization efforts performed by the Institute of Electrical and Electronics Engineers 802.15.6 task group before focusing on the two most popular types of technologies currently being considered for BANs, namely narrowband and Ultrawideband (UWB) communications. For narrowband communications the applicability of a generic path loss model is contended, before presenting some of the scenario specific models which have proven successful. The impacts of human body shadowing and small-scale fading are also presented alongside some of the most recent research into the Doppler and time dependencies of BANs. For UWB BAN communications, we again consider the path loss as well as empirical tap delay line models developed from a number of extensive channel measurement campaigns conducted by research institutions around the world. Ongoing efforts within collaborative projects such as Committee on Science and Technology Action IC1004 are also described. Finally, recent years have also seen significant developments in other areas of body centric communications such as off-body and body-to-body communications. We highlight some of the newest relevant research in these areas as well as discussing

  4. A review of radio channel models for body centric communications

    Science.gov (United States)

    Cotton, Simon L.; D'Errico, Raffaele; Oestges, Claude

    2014-06-01

    The human body is an extremely challenging environment for the operation of wireless communications systems, not least because of the complex antenna-body electromagnetic interaction effects which can occur. This is further compounded by the impact of movement and the propagation characteristics of the local environment which all have an effect upon body centric communications channels. As the successful design of body area networks (BANs) and other types of body centric system is inextricably linked to a thorough understanding of these factors, the aim of this paper is to conduct a survey of the current state of the art in relation to propagation and channel models primarily for BANs but also considering other types of body centric communications. We initially discuss some of the standardization efforts performed by the Institute of Electrical and Electronics Engineers 802.15.6 task group before focusing on the two most popular types of technologies currently being considered for BANs, namely narrowband and Ultrawideband (UWB) communications. For narrowband communications the applicability of a generic path loss model is contended, before presenting some of the scenario specific models which have proven successful. The impacts of human body shadowing and small-scale fading are also presented alongside some of the most recent research into the Doppler and time dependencies of BANs. For UWB BAN communications, we again consider the path loss as well as empirical tap delay line models developed from a number of extensive channel measurement campaigns conducted by research institutions around the world. Ongoing efforts within collaborative projects such as Committee on Science and Technology Action IC1004 are also described. Finally, recent years have also seen significant developments in other areas of body centric communications such as off-body and body-to-body communications. We highlight some of the newest relevant research in these areas as well as discussing

  5. Npl Ionospheric Model for Radio Communication and Navigational Applications

    Science.gov (United States)

    Singh Dabas, Raj

    In the areas of Radio Communication and Navigation, present day need of the users are to achieve higher performance communication, better navigation, positioning which can only be possible through improved Ionospheric Modeling, its now casting and forecast-ing. Therefore, National Physical Laboratory (NPL), New Delhi has develop a user friendly, Empirical Ionospheric Model (NPL Model) for the Indian zone which gives all the F-region Parameters like foF2, NmF2, hmF2, Ne Profiles and the Ionospheric Electron Content (IEC) for different Radio Communication/Navigational applications. Basically, two HF prediction models for short and long term predictions are developed for equatorial and low latitude iono-sphere. Short term HF prediction model is based on Multiple Regression Analysis (MRA) for the dependence of F-region parameters namely foF2 and M(3000)F2, on solar 2800 MHz flux (F10), and geomagnetic index Ap whereas for long term prediction, Second Degree (SD) coefficients are generated by fitting monthly median foF2 and M(3000)F2 with corresponding 12 monthly mean sunspot numbers (R12) using data over three solar cycles. For generating MRA coefficients, daily foF2, M(3000)F2 values for each hour, obtained from Delhi (28.6N, 77.1E) digital ionosonde for about half a solar cycle are used. MRA coefficients, separately for quiet (Ap25) periods, for foF2 and M(3000)F2, are obtained for every month over 24 UT times using daily F10 and Ap values. Whereas SD coefficients are obtained each month at all local times for all the 14 stations covering a geographic latitude range from about 0 to 45 N. IEC model is developed in two ways. Firstly, IEC model is also developed using monthly median foF2 and hmF2 values for each hours for all the 14 stations which are feed into IRI 2000 model to calculate respective IEC values for two altitudes namely 1000km and 2000km. Then, second degree coefficients are generated by fitting monthly median IEC with corresponding 12 monthly mean

  6. Annual report 1992/93, FOA 38. Radio systems and wave propagation

    Science.gov (United States)

    Mildh, I. M.

    1994-01-01

    The main objective of the division of Radio Systems and Wave Propagation is to carry out research and development in the field of secure and robust radio communications for Sweden's national defense. This is the Annual Report for fiscal year 1992/93 of the Division of Radio Systems and Wave Propagation. The division is responsible for research and development of secure radio communication for information transmission. We are also responsible for wave propagation research within a frequency range from LF to SHF. We carry out applied research in fields like antijamming systems, modulation, error correcting codes, wave propagation and digital signal processing. The wave propagation research is carried out by basic research so the demands from new techniques and new radio systems for accurate propagation models can be achieved.

  7. Communication system for emergency

    Energy Technology Data Exchange (ETDEWEB)

    Ajioka, Yoshiteru [Shizuoka Prefecture (Japan)

    1996-12-01

    People are apprehensive that a strong earthquake with a magnitude of nearly 8 may occur in Tokai area. The whole area of Shizuoka Prefecture has been specified as the specially strengthened region for earthquake disaster measures. This report outlines the communication system for emergency with respect to atomic disaster caused by an earthquake. Previously, wireless receiving system is stationed in the whole area to simultaneously inform the related news to the residents and so, communications with them are possible at any time by using the system. Since mobile wireless receiving sets are stationed in all town halls, self defense organizations and all the places of refuge, mutual communications are possible. These communication system can be utilized for either earthquake or nuclear disaster. Further, Shizuoka general information network system has been established as a communication system for anti-disaster organization and a wireless network via a communication satellite, ``super bird`` has been constructed in addition to the ground network. Therefore, the two communication routes became usable at emergency and the systems are available in either of nuclear disaster or earthquake. (M.N.)

  8. Radio frequency interference protection of communications between the Deep Space Network and deep space flight projects

    Science.gov (United States)

    Johnston, D. W. H.

    1981-01-01

    The increasing density of electrical and electronic circuits in Deep Space Station systems for computation, control, and numerous related functions has combined with the extension of system performance requirements calling for higher speed circuitry along with broader bandwidths. This has progressively increased the number of potential sources of radio frequency interference inside the stations. Also, the extension of spectrum usage both in power and frequency as well as the greater density of usage at all frequencies for national and international satellite communications, space research, Earth resource operations and defense, and particularly the huge expansion of airborne electronic warfare and electronic countermeasures operations in the Mojave area have greatly increased the potential number and severity of radio frequency interference incidents. The various facets of this problem and the efforts to eliminate or minimize the impact of interference on Deep Space Network support of deep space flight projects are described.

  9. Wireless Augmented Reality Communication System

    Science.gov (United States)

    Devereaux, Ann (Inventor); Jedrey, Thomas (Inventor); Agan, Martin (Inventor)

    2016-01-01

    The system of the present invention is a highly integrated radio communication system with a multimedia co-processor which allows true two-way multimedia (video, audio, data) access as well as real-time biomedical monitoring in a pager-sized portable access unit. The system is integrated in a network structure including one or more general purpose nodes for providing a wireless-to-wired interface. The network architecture allows video, audio and data (including biomedical data) streams to be connected directly to external users and devices. The portable access units may also be mated to various non-personal devices such as cameras or environmental sensors for providing a method for setting up wireless sensor nets from which reported data may be accessed through the portable access unit. The reported data may alternatively be automatically logged at a remote computer for access and viewing through a portable access unit, including the user's own.

  10. Towards Energy Efficient Cognitive Radio Systems

    KAUST Repository

    Alabbasi, AbdulRahman

    2016-07-14

    Cognitive radio (CR) is a cutting-edge wireless communication technology that adopts several existing communication concepts in order to efficiently utilize the spectrum and meet the users demands of high throughput and real-time systems. Conventionally, high throughput demands are met through adopting broadband and multi-antenna technologies such as, orthogonal frequency division multiplexing (OFDM) and Multi-Input Multi-Output (MIMO). Whereas, real-time application demands are met by analyzing metrics which characterize the delay limited channels, such as, outage probability over block-fading channels. Being an environmental friendly technology, energy efficiency metrics should be considered in the design of a CR application. This thesis tackles the energy efficiency of CR system from different aspects, utilizing different measuring metrics and constrains. Under the single-input single-output (SISO) OFDM we minimized the energy per goodbit (EPG) metric subject to several power and Quality of Service (QoS) constraints. In this approach, the minimum EPG metric is optimized via proposing two optimal and sub-optimal resource allocation schemes. We consider several parameters as optimization variables, such as, power policy, sensing threshold, and channel quality threshold. We also captured the impact of involving the media access control (MAC) layers parameters, such as, frame length, in the minimization of a modified EPG metric. Also, a MAC protocol, i.e., hybrid automatic repeat request (HARQ), and the associated power consumption of the retransmission mechanism is considered in the formulation of the problem. In this context, the optimal power and frame length are derived to minimize the modified EPG while considering several spectrum-sharing scenarios, which depend on sensing information. In MIMO based CR system, we maximized capacity to power ratio (CPR) (as an energy efficiency (EE) metric) subject to several power and QoS constraints. In this context, the

  11. Reconfigurable Transceiver and Software-Defined Radio Architecture and Technology Evaluated for NASA Space Communications

    Science.gov (United States)

    Reinhart, Richard C.; Kacpura, Thomas J.

    2004-01-01

    The NASA Glenn Research Center is investigating the development and suitability of a software-based open-architecture for space-based reconfigurable transceivers (RTs) and software-defined radios (SDRs). The main objectives of this project are to enable advanced operations and reduce mission costs. SDRs are becoming more common because of the capabilities of reconfigurable digital signal processing technologies such as field programmable gate arrays and digital signal processors, which place radio functions in firmware and software that were traditionally performed with analog hardware components. Features of interest of this communications architecture include nonproprietary open standards and application programming interfaces to enable software reuse and portability, independent hardware and software development, and hardware and software functional separation. The goals for RT and SDR technologies for NASA space missions include prelaunch and on-orbit frequency and waveform reconfigurability and programmability, high data rate capability, and overall communications and processing flexibility. These operational advances over current state-of-art transceivers will be provided to reduce the power, mass, and cost of RTs and SDRs for space communications. The open architecture for NASA communications will support existing (legacy) communications needs and capabilities while providing a path to more capable, advanced waveform development and mission concepts (e.g., ad hoc constellations with self-healing networks and high-rate science data return). A study was completed to assess the state of the art in RT architectures, implementations, and technologies. In-house researchers conducted literature searches and analysis, interviewed Government and industry contacts, and solicited information and white papers from industry on space-qualifiable RTs and SDRs and their associated technologies for space-based NASA applications. The white papers were evaluated, compiled, and

  12. Control and Non-Payload Communications (CNPC) Prototype Radio - Generation 2 Flight Test Report

    Science.gov (United States)

    Ishac, Joseph A.; Iannicca, Dennis C.; Shalkhauser, Kurt A.; Kachmar, Brian A.

    2014-01-01

    NASA Glenn Research Center conducted a series of flight tests for the purpose of evaluating air-to-ground communications links for future unmanned aircraft systems (UAS). The primary objective of the test effort was to evaluate the transition of the aircraft communications from one ground station to the next, and to monitor data flow during the "hand-off" event. To facilitate the testing, ground stations were installed at locations in Cleveland, Ohio and Albany, Ohio that each provides line-of-sight radio communications with an overflying aircraft. This report describes results from the flight tests including flight parameters, received signal strength measurements, data latency times, and performance observations for the air-to-ground channel.

  13. AMPA experimental communications systems

    Science.gov (United States)

    Beckerman, D.; Fass, S.; Keon, T.; Sielman, P.

    1982-01-01

    The program was conducted to demonstrate the satellite communication advantages of Adaptive Phased Array Technology. A laboratory based experiment was designed and implemented to demonstrate a low earth orbit satellite communications system. Using a 32 element, L-band phased array augmented with 4 sets of weights (2 for reception and 2 for transmission) a high speed digital processing system and operating against multiple user terminals and interferers, the AMPA system demonstrated: communications with austere user terminals, frequency reuse, communications in the face of interference, and geolocation. The program and experiment objectives are described, the system hardware and software/firmware are defined, and the test performed and the resultant test data are presented.

  14. A Simple Radio Receiver Aids Understanding of Wireless Communication

    Science.gov (United States)

    Straulino, S.; Orlando, A.

    2012-01-01

    The basic theory of radio broadcasting is discussed from an experimental point of view. First, concepts like wave modulation and tuning are explained with the use of instruments in the physics laboratory. Then, a very basic radio receiver is described and assembled, whose most important feature, like in the old "crystal radios", is the absence of…

  15. A Modified Energy Detection Based Spectrum Sensing Algorithm for Green Cognitive Radio Communication

    Directory of Open Access Journals (Sweden)

    Sidra Rajput

    2015-10-01

    Full Text Available Spectrum Sensing is the first and fundamental function of Cognitive Cycle which plays a vital role in the success of CRs (Cognitive Radios. Spectrum Sensing indicate the presence and absence of PUs (Primary Users in RF (Radio Frequency spectrum occupancy measurements. In order to correctly determine the presence and absence of Primary Users, the algorithms in practice include complex mathematics which increases the computational complexity of the algorithm, thus shifted the CRs to operate as ?green? communication systems. In this paper, an energy efficient and computationally less complex, energy detection based Spectrum Sensing algorithm have been proposed. The design goals of the proposed algorithm are to save the processing and sensing energies. At first, by using less MAC (Multiply and Accumulate operation, it saves the processing energy needed to determine the presence and absence of PUs. Secondly, it saves the sensing energy by providing a way to find lowest possible sensing time at which spectrum is to be sensed. Two scenarios have been defined for testing the proposed algorithm i.e. simulate detection capability of Primary Users in ideal and noisy scenarios. Detection of PUs in both of these scenarios have been compared to obtain the probability of detection. Energy Efficiency of the proposed algorithm has been proved by making performance comparison between the proposed (less complex algorithm and the legacy energy detection algorithm. With reduced complexity, the proposed spectrum sensing algorithm can be considered under the paradigm of Green Cognitive Radio Communication

  16. OptoRadio: a method of wireless communication using orthogonal M-ary PSK (OMPSK) modulation

    Science.gov (United States)

    Gaire, Sunil Kumar; Faruque, Saleh; Ahamed, Md. Maruf

    2016-09-01

    Laser based radio communication system, i.e. OptoRadio, using Orthogonal M-ary PSK Modulation scheme is presented in this paper. In this scheme, when a block of data needs to be transmitted, the corresponding block of biorthogonal code is transmitted by means of multi-phase shift keying. At the receiver, two photo diodes are cross coupled. The effect is that the net output power due to ambient light is close to zero. The laser signal is then transmitted only into one of the receivers. With all other signals being cancelled out, the laser signal is an overwhelmingly dominant signal. The detailed design, bit error correction capabilities, and bandwidth efficiency are presented to illustrate the concept.

  17. Assessing Evaporation Duct Variability In The Eastern Mediterranean Sea In Support Of Radar And Radio Communications

    Science.gov (United States)

    2016-12-01

    EVAPORATION DUCT VARIABILITY IN THE EASTERN MEDITERRANEAN SEA IN SUPPORT OF RADAR AND RADIO COMMUNICATIONS by Süleyman C. Gürbüz December 2016...MEDITERRANEAN SEA IN SUPPORT OF RADAR AND RADIO COMMUNICATIONS 5. FUNDING NUMBERS 6. AUTHOR(S) Süleyman C. Gürbüz 7. PERFORMING ORGANIZATION NAME(S...IN THE EASTERN MEDITERRANEAN SEA IN SUPPORT OF RADAR AND RADIO COMMUNICATIONS Süleyman C. Gürbüz Lieutenant Junior Grade, Turkish Navy B.S

  18. Digital communication system

    Science.gov (United States)

    Monford, L. G., Jr. (Inventor)

    1974-01-01

    A digital communication system is reported for parallel operation of 16 or more transceiver units with the use of only four interconnecting wires. A remote synchronization circuit produces unit address control words sequentially in data frames of 16 words. Means are provided in each transceiver unit to decode calling signals and to transmit calling and data signals. The transceivers communicate with each other over one data line. The synchronization unit communicates the address control information to the transceiver units over an address line and further provides the timing information over a clock line. A reference voltage level or ground line completes the interconnecting four wire hookup.

  19. Multi-carrier transmission for hybrid radio frequency with optical wireless communications

    Science.gov (United States)

    Wang, Gang; Chen, Genshe; Shen, Dan; Pham, Khanh; Blasch, Erik; Nguyen, Tien M.

    2015-05-01

    Radio frequency (RF) wireless communication is reaching its capacity to support large data rate transmissions due to hardware constraints (e.g., silicon processes), software strategies (e.g., information theory), and consumer desire for timely large file exchanges (e.g., big data and mobile cloud computing). A high transmission rate performance must keep pace with the generated huge volumes of data for real-time processing. Integrated RF and optical wireless communications (RF/OWC) could be the next generation transmission technology to satisfy both the increased data rate exchange and the communications constraints. However, with the promising benefits of RF/OWC, challenges remain to fully develop hybrid RF with wireless optical communications such as uniform waveform design for information transmission and detection. In this paper, an orthogonal frequency division multiplexing (OFDM) transmission scheme, which widely employed in RF communications, is developed for optical communications. The traditional high peak-to-average power ratio (PAPR) in OFDM is reduced to improve system performance. The proposed multi-carrier waveform is evaluated with a frequency-selective fading channel. The results demonstrate that bit error rate (BER) performance of our proposed optical OFDM transmission technique outperforms the traditional OWC on-off keying (OOK) transmission scheme.

  20. The Evolution of Communication Systems

    OpenAIRE

    2010-01-01

    One can study communications by using Shannon's (1948) mathematical theory of communication. In social communications, however, the channels are not "fixed", but themselves subject to change. Communication systems change by communicating information to related communication systems; co-variation among systems if repeated over time, can lead to co-evolution. Conditions for stabilization of higher-order systems are specifiable: segmentation, stratification, differentiation, reflection, and self...

  1. The Hitachi and Takahagi 32 m radio telescopes: Upgrade of the antennas from satellite communication to radio astronomy

    Science.gov (United States)

    Yonekura, Yoshinori; Saito, Yu; Sugiyama, Koichiro; Soon, Kang Lou; Momose, Munetake; Yokosawa, Masayoshi; Ogawa, Hideo; Kimura, Kimihiro; Abe, Yasuhiro; Nishimura, Atsushi; Hasegawa, Yutaka; Fujisawa, Kenta; Ohyama, Tomoaki; Kono, Yusuke; Miyamoto, Yusuke; Sawada-Satoh, Satoko; Kobayashi, Hideyuki; Kawaguchi, Noriyuki; Honma, Mareki; Shibata, Katsunori M.; Sato, Katsuhisa; Ueno, Yuji; Jike, Takaaki; Tamura, Yoshiaki; Hirota, Tomoya; Miyazaki, Atsushi; Niinuma, Kotaro; Sorai, Kazuo; Takaba, Hiroshi; Hachisuka, Kazuya; Kondo, Tetsuro; Sekido, Mamoru; Murata, Yasuhiro; Nakai, Naomasa; Omodaka, Toshihiro

    2016-10-01

    The Hitachi and Takahagi 32 m radio telescopes (former satellite communication antennas) were so upgraded as to work at 6, 8, and 22 GHz. We developed the receiver systems, IF systems, back-end systems (including samplers and recorders), and reference systems. We measured the performance of the antennas. The system temperature including the atmosphere toward the zenith, T_sys^{ast }, is measured to be ˜30-40 K for 6 GHz and ˜25-35 K for 8 GHz. T_sys^{ast } for 22 GHz is measured to be ˜40-100 K in winter and ˜150-500 K in summer seasons, respectively. The aperture efficiency is 55%-75% for Hitachi at 6 GHz and 8 GHz, and 55%-65% for Takahagi at 8 GHz. The beam sizes at 6 GHz and 8 GHz are ˜4.6° and ˜3.8°, respectively. The side-lobe level is less than 3%-4% at 6 and 8 GHz. Pointing accuracy was measured to be better than ˜0.3° for Hitachi and ˜0.6° for Takahagi. We succeeded in VLBI observations in 2010 August, indicating good performance of the antenna. We started single-dish monitoring observations of 6.7 GHz methanol maser sources in 2012 December, and found several new sources showing short-term periodic variation of the flux density.

  2. Estimation of the Potential Interference Immunity of Radio Reception with Spatial Signal Processing in Multipath Radio-Communication Channels. I. Decameter Range

    Science.gov (United States)

    Metelev, S. A.; Lvov, A. V.

    2016-09-01

    We propose a method for estimating potential interference immunity of radio reception in the multipath radio-communication channels. Using this method for the modified Watterson model of the decameter radio channel, we study the achievable interference immunity of devices with spatial signal processing.

  3. [Problems of harmonization of sanitary regulations of the electromagnetic fields of mobile radio communication equipment].

    Science.gov (United States)

    Pal'tsev, Iu P; Pokhodzeĭ, L V; Rubtsova, N B; Bogacheva, E V

    2013-01-01

    In the article there are presented data on the probable adverse effects of electromagnetic fields generated by means of mobile cellulary radio communication equipment, a comparative analysis of hygienic rating and methods of measurement of their parameters in Russia and abroad has been performed, and the ways of harmonizing hygienic rules have been outlined, the necessity of further research to risk assessment of the use of cellular radio communication devices by population and preventive measures have been substantiated.

  4. DYMAC communications system

    Energy Technology Data Exchange (ETDEWEB)

    Lindsey, K.A.

    1980-01-01

    The DYMAC Communications System is part of a nuclear safeguards system called DYMAC - short for DYnamic Materials ACcountability - that gathers accountability information at the Los Alamos Scientific Laboratory (LASL) Plutonium Processing Facility. The communications system handles transmissions between data-entry terminals and nondestructive assay (NDA) instruments located in the facility, and a computer located in an adjacent building. System design emphasizes reliability rather than high speed to ensure the integrity of data transmissions. This manual is directed toward the person responsible for maintaining the DYMAC Communication System. It describes the components that make up the communications network, explains how they operate, and gives detailed information about all of the connections. Many of the system components are commercially available; some have been modified at LASL for DYMAC purposes; others were designed and fabricated at LASL. This manual provides circuit diagrams for all of the LASL modifications and LASL-fabricated equipment. In addition, it provides a series of procedures for tracing cables, reconfiguring various parts of the system, testing data transmissions, and troubleshooting malfunctions.

  5. Toward a Gigabit Wireless Communications System

    CERN Document Server

    Rakotondrainibe, Lahatra; Zaharia, Gheorghe; Zein, Ghaïs El

    2009-01-01

    This paper presents the design and the realization of a hybrid wireless Gigabit Ethernet indoor communications system operating at 60 GHz. As the 60 GHz radio link operates only in a single-room configuration, an additional Radio over Fiber (RoF) link is used to ensure the communications within all the rooms of a residential environment. The system uses low complexity baseband processing modules. A byte synchronization technique is designed to provide a high value of the preamble detection probability and a very small value of the false detection probability. Conventional RS (255, 239) encoder and decoder are used for channel forward error correction (FEC). The FEC parameters are determined by the tradeoff between higher coding gain and hardware complexity. The results of bit error rate measurements at 875 Mbps are presented for various antennas configurations.

  6. Airborne wireless communication systems, airborne communication methods, and communication methods

    Science.gov (United States)

    Deaton, Juan D [Menan, ID; Schmitt, Michael J [Idaho Falls, ID; Jones, Warren F [Idaho Falls, ID

    2011-12-13

    An airborne wireless communication system includes circuitry configured to access information describing a configuration of a terrestrial wireless communication base station that has become disabled. The terrestrial base station is configured to implement wireless communication between wireless devices located within a geographical area and a network when the terrestrial base station is not disabled. The circuitry is further configured, based on the information, to configure the airborne station to have the configuration of the terrestrial base station. An airborne communication method includes answering a 911 call from a terrestrial cellular wireless phone using an airborne wireless communication system.

  7. Pulsed radio frequency interference effects on data communications via satellite transponder

    Science.gov (United States)

    Weinberg, A.; Hong, Y.

    1979-01-01

    Power-limited communication links may be susceptible to significant degradation if intentional or unintentional pulsed high level radio frequency interference (RFI) is present. Pulsed RFI is, in fact, of current interest to NASA in studies relating to its Tracking and Data Relay Satellite System (TDRSS). The present paper examines the impact of pulsed RFI on the error probability performance of a power-limited satellite communication link: the assumed modulation scheme is PN coded binary PSK. The composite effects of thermal noise, pulsed CW and pulsed Gaussian noise are analyzed, where RFI arrivals are assumed to follow Poisson statistics. Under the assumption that the satellite repeater is ideal and that integrate and dump filtering is employed at the ground receiver, an exact error probability expression and associated approximations are derived. Computed results are generated using an arbitrarily specified RFI model.

  8. When all else fails: 21st century Amateur Radio as an emergency communications medium.

    Science.gov (United States)

    Nollet, Kenneth E; Ohto, Hitoshi

    2013-12-01

    Twenty-first century demand for radio spectrum continues to increase with the explosive growth of wireless devices, but authorities reserve slices of the spectrum for licensed Amateur Radio operators, recognizing their value to the public, particularly with respect to providing emergency communications. Blood banking and transfusion medicine are among the specialties that should also recognize the value of Amateur Radio as an emergency communications medium, because blood collection, testing, processing, storage, and transfusion are life-saving activities that in modern times can be separated by considerable distance.

  9. The paraboloidal reflector antenna in radio astronomy and communication theory and practice

    CERN Document Server

    Baars, Jacob W M

    2007-01-01

    Reflector antennas are widely used in the microwave and millimeter wavelength domain. Radio astronomers have developed techniques of calibration of large antennas with radio astronomical methods. These have not been comprehensively described. This text aims to fill this gap. The Paraboloidal Reflector Antenna in Radio Astronomy and Communication: Theory and Practice takes a practical approach to the characterization of antennas. All calculations and results in the form of tables and figures have been made with Mathematica by Wolfram Research. The reader can use the procedures for the implementation of his/her own input data. The book should be of use to all who are involved in the design and calibration of large antennas, like ground station managers and engineers, practicing radio astronomers, and finally, graduate students in radio astronomy and communication technology.

  10. The software system ``Evolution of radio galaxies''

    Science.gov (United States)

    Verkhodanov, O. V.; Kopylov, A. I.; Zhelenkova, O. P.; Verkhodanova, N. V.; Chernenkov, V. N.; Parijskij, Yu. N.; Soboleva, N. S.; Temirova, A. V.

    The project of the informational system creation on the problem of evolution of radio galaxies is described. This system, being developed at present at the server http://sed.sao.ru, allows a user to operate with simulated curves of spectral energy distributions (SED) and to estimate ages and redshifts by photometric data using χ2-method. Authors use SEDs of several models (GISSEL'98 (Bruzual, Charlot, 1996), PEGASE (Fioc, Rocca-Volmerange, 1996, 1998)) for different types of galaxies. Synthetic spectra are smoothed by the filter sensetivity curves before the procedure of age estimation. There is a possibility to calculate extictions in different filters using infrared maps. The server containes full archive of RC-catalog radio galaxy images obtained with 6 m telescope of SAO and VLA data. Modes of HTTP, FTP and FTP access, formats of output result (TABLE and GNUPLOT graphic) and additional functions are described.

  11. System to Study Evolution of Radio Galaxies

    Science.gov (United States)

    Verkhodanova, N. V.; Verkhodanov, O. V.; Kopylov, A. I.; Zhelenkova, O. P.; Chernenkov, V. N.; Parijskij, Yu. N.; Soboleva, N. S.; Temirova, A. V.

    The project of the informational system creation on the problem of evolution of radio galaxies is described. This system, being developed at present at the server http:// sed.sao.ru, allows a user to operate with simulated curves of spectral energy distributions (SED) and to estimate ages and redshifts by photometric data using χ2-method. Authors use SEDs of several models (GISSEL'98 (Bruzual, Charlot, 1996), PEGASE (Fioc, Rocca-Volmerange, 1996, 1998)) for different types of galaxies. Synthetic spectra are smoothed by the filter sensetivity curves before the procedure of age estimation. There is a possibility to calculate extictions in different filters using infrared maps. The server containes full archive of RC-catalog radio galaxy images obtained with 6 m telescope of SAO and VLA data. Modes of HTTP, FTP and FTP access, formats of output result (TABLE and GNUPLOT graphic) and additional functions are described.

  12. Next Generation Radio Astronomy Receiver Systems

    CERN Document Server

    Morgan, Matthew A

    2009-01-01

    Radio astronomy observations in the coming decade will require new levels of sensitivity while mapping large regions of space with much greater efficiency than is achieved with current telescopes. This requires new instrumentation with the greatest achievable sensitivity, dynamic range, and field of view. Receiver noise is quickly approaching fundamental limits at most radio wavelengths, so significant gains in sensitivity can only be made by increasing collecting area. Jointly, these requirements suggest using large arrays of smaller antennas, or many moderate-size antennas equipped with multi-beam arrays. The challenge is to develop receivers and wide bandwidth data transport systems which are lower cost, more compact, more reliable, lower weight, and more reproducible than the best current systems, with no compromise to performance. This can be achieved with a greater degree of component integration, extensive use of digital signal processing and transport, and replacement of functions currently performed ...

  13. The Educational Project for Media Literacy Using Radio Broadcasting System

    OpenAIRE

    北村, 順生; Kitamura, Yorio

    2009-01-01

    This report outlines the educational project for media literacy using radio broadcasting system. The practical activity to produce a radio program are very effective on the students to cultivate their media literacy.

  14. Bolidozor - Distributed radio meteor detection system

    CERN Document Server

    Kakona, Jakub; Kakona, Martin

    2016-01-01

    Most of the meteor radioastronomical radars are backscatter radars which cover only a small area of the atmosphere. Therefore a daytime meteor flux models are based on sparse data collected by only a few radar systems. To solve this issue, a radar system with a wide coverage is required. We present a new approach of open-source multi-static radio meteor detection system which could be distributed over a large area. This feature allows us to detect meteor events taking place over a larger area as well and gather more uniform data about meteor flux and possibly about meteor trajectories.

  15. Radio emission from RS CVn binary systems

    Energy Technology Data Exchange (ETDEWEB)

    Doiron, D.J.

    1984-01-01

    The RS CVn binary stellar systems UX Ari, HR 1099, AR Lac, HR 5110, II Peg, lambda And, and SZ Psc were investigated by use of radio interferometry during the period from July 1982 through August 1983. Interferometry took two forms: Very Large Array (VLA) observations and Very Long Baseline Interferometry (VLBI). The VLA observations determined the characteristic polarization and flux behavior of the centimeter wavelength radio emission. The observed spectral index was near zero during quiescent periods, rising to between 0.5 and 1.0 during active periods. No net linear polarization is observed to a limit of 1.7%. This is expected since the Faraday depth of thermal electrons deduced from x-ray observations is approx. 10/sup 5/. Circular polarization is observed to be less than 20% at all frequencies often with a helicity reversal between 1.6 GHz and 5 GHz. The VLBI observations have shown that the brightness temperatures are often T/sub B/ approx.> 10/sup 10/ /sup 0/K and size sources smaller than or comparable to the overall size of the binary system. These data are consistent with incoherent gyrosynchrotron emission from mildly relativistic electrons which are optically thick to their own radiation at 1.6 GHz and optically thin at 5 GHz and above. The spectral behavior suggests that the radio emission is due to a power-law distribution of electrons.

  16. Communication Facilities for Distributed Systems

    Directory of Open Access Journals (Sweden)

    V. Barladeanu

    1997-01-01

    Full Text Available The design of physical networks and communication protocols in Distributed Systems can have a direct impact on system efficiency and reliability. This paper tries to identify efficient mechanisms and paradigms for communication in distributed systems.

  17. Cooperative Cognitive Radio Systems over Nakagami-m Fading Channels

    KAUST Repository

    Hyadi, Amal

    2013-05-08

    This thesis aims to investigate the incorporation of cooperative techniques in cognitive radio networks over Nakagami-m fading channels. These last years, spectrum sharing mechanisms has gained a lot of interest in the wireless communication domain. Using cooperation in a cognitive set up make the use of spectrum much more efficient. Moreover, it helps to extend the coverage area of the cognitive network and also to reduce the transmitting power and, thus, the generated interference. In this work, we consider two particular scenarios for cooperative cognitive radio systems. The first scenario consider multihop regenerative relaying in an underlay cognitive set up. The cooperation is performed in the secondary system, in the presence of multiple primary users. Both interference power and peak power constraints are taking into account. Closed-form expressions for the statistical characteristics and multiple end- to-end performance metrics are derived. Different scenarios are presented to illustrate the obtained results and Monte Carlo simulations confirm the accuracy of our analytical derivations. In the second part of this work, we consider an overlay cognitive network with the spectrally efficient two-phase two-way relaying protocol. Two relay selection techniques, optimizing both the primary and the secondary communication, are presented. The overall outage performance is investigated and an optimal power allocation scheme, that ameliorate the outage performance of the system, is proposed. Numerical simulations are presented to illustrate and compare the obtained results.

  18. Influence of satellite vibration on radio over IsOWC system

    Science.gov (United States)

    Zong, Kang; Zhu, Jiang

    2017-07-01

    In this paper, we analyze the influence of satellite vibration on radio over intersatellite optical wireless communication (IsOWC) system with an optical booster amplifier (OBA) and an optical preamplifier. The closed-form expressions of radio frequency (RF) gain, noise figure (NF) and spurious-free dynamic range (SFDR) are derived in the presence of pointing jitter taking consideration of bias error. Numerical results for RF gain, NF and SFDR are given for demonstration. Results indicate that the bias error obviously deteriorates the performance of the radio over IsOWC system.

  19. The Radio Frequency Health Node Wireless Sensor System

    Science.gov (United States)

    Valencia, J. Emilio; Stanley, Priscilla C.; Mackey, Paul J.

    2009-01-01

    The Radio Frequency Health Node (RFHN) wireless sensor system differs from other wireless sensor systems in ways originally intended to enhance utility as an instrumentation system for a spacecraft. The RFHN can also be adapted to use in terrestrial applications in which there are requirements for operational flexibility and integrability into higher-level instrumentation and data acquisition systems. As shown in the figure, the heart of the system is the RFHN, which is a unit that passes commands and data between (1) one or more commercially available wireless sensor units (optionally, also including wired sensor units) and (2) command and data interfaces with a local control computer that may be part of the spacecraft or other engineering system in which the wireless sensor system is installed. In turn, the local control computer can be in radio or wire communication with a remote control computer that may be part of a higher-level system. The remote control computer, acting via the local control computer and the RFHN, cannot only monitor readout data from the sensor units but can also remotely configure (program or reprogram) the RFHN and the sensor units during operation. In a spacecraft application, the RFHN and the sensor units can also be configured more nearly directly, prior to launch, via a serial interface that includes an umbilical cable between the spacecraft and ground support equipment. In either case, the RFHN wireless sensor system has the flexibility to be configured, as required, with different numbers and types of sensors for different applications. The RFHN can be used to effect realtime transfer of data from, and commands to, the wireless sensor units. It can also store data for later retrieval by an external computer. The RFHN communicates with the wireless sensor units via a radio transceiver module. The modular design of the RFHN makes it possible to add radio transceiver modules as needed to accommodate additional sets of wireless sensor

  20. Amended (Wavelet Multiband OFDM Cognitive Radio System

    Directory of Open Access Journals (Sweden)

    J. Avila

    2015-05-01

    Full Text Available This study focuses on improving the functioning of multiband Orthogonal Frequency Division Multiplexing (OFDM system by utilizing wavelet transform as a substitute to Fast Fourier Transform (FFT. The performance is further refined by apt inclusion of modulation technique. Error control codes are utilized which aims at the removal of error from the transmitted bits. In addition to attain diversity Alamouti code is concatenated with error control codes. OFDM is the best fit for cognitive radio and sensing the free holes is the key task of any cognitive system. This study additionally also analyses the performance of energy detection based spectrum sensing in the presence of various noise models.

  1. Smart Data Node in the Sky (SDNITS): communications system

    Science.gov (United States)

    Kantak, A.; Lansing, F.

    2003-01-01

    In this paper we will discuss: the steps for adequately designing such a complex telecommunications system 'Smart Data Node In The Sky (SDNITS)'; algorithm development for this process; specifications to be levied on the interfacing subsystems; type of the system e.g., the usual Radio Frequency system or a laser communications system.

  2. Smart Data Node in the Sky (SDNITS): communications system

    Science.gov (United States)

    Kantak, A.; Lansing, F.

    2003-01-01

    In this paper we will discuss: the steps for adequately designing such a complex telecommunications system 'Smart Data Node In The Sky (SDNITS)'; algorithm development for this process; specifications to be levied on the interfacing subsystems; type of the system e.g., the usual Radio Frequency system or a laser communications system.

  3. Chaotic communication in radio-over-fiber transmission based on optoelectronic feedback semiconductor lasers.

    Science.gov (United States)

    Lin, Fan-Yi; Tsai, Meng-Chiao

    2007-01-22

    Performance of chaotic communication in radio-over-fiber (ROF) transmission based on optoelectronic feedback semiconductor lasers is studied numerically. The chaotic carrier is generated by optoelectronic feedback semiconductor lasers, where chaotic communication is realized by synchronizing a receiver laser with a transmitter laser. Transmission quality of different message encoding schemes, including additive chaos modulation (ACM) and on-off shift keying (OOSK), are investigated and compared. In this study, the dispersion and nonlinearity effects in the fiber transmission module and the amplified spontaneous emission noise from the optical amplifiers are considered. In the wireless channel, effects of additive white Gaussian noise, multipath, and path loss are included. To quantitatively study the performance of this chaotic communication system in the ROF transmission, bit-error-rates (BER) of different transmission lengths, message bit-rates, and signal-to-noise ratios are studied. The optimal launched power and message strength that minimize the BER while assuring effective communication security are discussed. While the ACM scheme is shown to perform better in a fiber only configuration, the OOSK scheme shows better immunity to the random effects and waveform distortions presented in the wireless channel.

  4. Space Telecommunications Radio System (STRS) Definitions and Acronyms

    Science.gov (United States)

    Briones, Janette C.; Handler, Louis M.; Johnson, Sandra K.; Nappier, Jennifer; Gnepp, Steven; Kacpura, Thomas J.; Reinhart, Richard C.; Hall, Charles S.; Mortensen, Dale

    2008-01-01

    Software-defined radio is a relatively new technology area, and industry consensus on terminology is not always consistent. Confusion exists when the various organizations and standards bodies define different radio terms associated with the actual amount of reconfigurability of the radios. The Space Telecommunications Radio System (STRS) Definitions and Acronyms Document provides the readers of the STRS documents a common understanding of the terminology used and how they will be applied to the STRS architecture.

  5. Airborne system for detection and location of radio interference sources

    Science.gov (United States)

    Audone, Bruno; Pastore, Alberto

    1992-11-01

    The rapid expansion of telecommunication has practically saturated every band of Radio Frequency Spectrum; a similar expansion of electrical and electronic devices has affected all radio communications which are, in some way, influenced by a large amount of interferences, either intentionally or unintentionally produced. Operational consequences of these interferences, particularly in the frequency channels used for aeronautical services, can be extremely dangerous, making mandatory a tight control of Electromagnetic Spectrum. The present paper analyzes the requirements and the problems related to the surveillance, for civil application, of the Electromagnetic Spectrum between 20 and 1000 MHz, with particular attention to the detection and location of radio interference sources; after a brief introduction and the indication of the advantages of an airborne versus ground installation, the airborne system designed by Alenia in cooperation with Italian Ministry of Post and Telecommunication, its practical implementation and the prototype installation on board of a small twin turboprop aircraft for experimentation purposes is presented. The results of the flight tests are also analyzed and discussed.

  6. Radio Frequency Simulation System (RFSS) Capabilities Summary

    Science.gov (United States)

    1977-04-01

    S- 0LEVEL-- TECHNICAL REPORT TD -77-8 RADIO FREQUENCY SIMULATION SYSTEM (RFSS) CAPABILITIES SUMMARY 00 SAeroballistios Directorate Advanced Simulation...gAttn: DRDMT - TD /AMCMS 63 303.214131101 RedstngArj gUAl. Alabmt 35809______________ It CONTITL.uNG OFFICE NAME AND ADDRESS CoMuaa ner US Army Missile...r ~- -- 0 0 0 1 N -4 -- -~ *5 0 - 5e41 -A I: a 00 I I. S Jto cc iI us V A U. II I’~z’LF~iJ - - - - -> 3-cc dc -4 -.40 =! Jo -AZC 4 C - 442q 0 M~A $Ji a

  7. Advanced Multimode Radio for Wireless & Mobile Broadband Communication

    DEFF Research Database (Denmark)

    Kardaras, Georgios; Lanzani, Christian

    2009-01-01

    of a digital predistortion (DPD) block is emphasized and an adaptive polynomial approach based on cartesian to polar conversion is then proposed. Such radio architecture has successfully been implemented on a low-cost FPGA family meeting the WiMAX/LTE spectrum and Error Vector Magnitude (EVM) requirements....

  8. Radio Channel Modelling for UAV Communication over Cellular Networks

    DEFF Research Database (Denmark)

    Amorim, Rafhael Medeiros de; Nguyen, Huan Cong; Mogensen, Preben Elgaard

    2017-01-01

    The main goal of this paper is to obtain models for path loss exponents and shadowing for the radio channel between airborne Unmanned Aerial Vehicles (UAVs) and cellular networks. In this pursuit, field measurements were conducted in live LTE networks at the 800 MHz frequency band, using...

  9. Development of radio dramas for health communication pilot intervention in Canadian Inuit communities.

    Science.gov (United States)

    Racicot-Matta, Cassandra; Wilcke, Markus; Egeland, Grace M

    2016-03-01

    A mixed-methods approach was used to develop a culturally appropriate health intervention over radio within the Inuit community of Pangnirtung, Nunavut (NU), Canada. The radio dramas were developed, recorded and tested pre-intervention through the use of Participatory Process and informed by the extended elaboration likelihood model (EELM) for education-communication. The radio messages were tested in two focus groups (n = 4 and n = 5) to determine fidelity of the radio dramas to the EELM theory. Focus group feedback identified that revisions needed to be made to two characteristics required of educational programmes by the EELM theorem: first, the quality of the production was improved by adding Inuit youth recorded music and second, the homophily (relatability of characters) of radio dramas was improved by re-recording the dramas with voices of local youth who had been trained in media communication studies. These adjustments would not have been implemented had pre-intervention testing of the radio dramas not taken place and could have reduced effectiveness of the overall intervention. Therefore, it is highly recommended that media tools for health communication/education be tested with the intended target audience before commencement of programmes. Participatory Process was identified to be a powerful tool in the development and sustainability of culturally appropriate community health programming.

  10. Improvement on control system of the JT-60 radio frequency heating system

    Energy Technology Data Exchange (ETDEWEB)

    Shinozaki, Shin-ichi; Moriyama, Shinichi; Hiranai, Shinichi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Sato, Fumiaki [Nippon Advanced Technology Co., Ltd., Tokai, Ibaraki (Japan)

    2003-03-01

    On the JT-60 radio frequency (RF) heating system, the decrease in the activity ratio was a problem because of the deterioration of the control system. To improve the reliability, we replaced CAMAC system for a power injection control system, which was a main cause of the trouble, with the microprocessor system. And, a function of computer supported programming function of RF power injection form was introduced, which contributed to reduce a load of operators. Furthermore, personal computers with network communication were introduced to improve a maintenance ability of the control system. As a result, the activity ratio of the RF heating system was improved significantly. (author)

  11. Fundamental energetic limits of radio communication systems

    Science.gov (United States)

    Baudais, Jean-Yves

    2017-02-01

    The evaluation of the energy consumption of a radiocommunication requires to analyse the life cycle of the elements used. However, this analysis does not specify the energetic limits. Theoretical approaches allow one to draw these limits, which are known in multiple cases of information transmission. However, the answers are not always satisfactory, in particular in the case of time-varying channels. After a brief presentation of the notion of energetic limits of a radiocommunication, and beginning with a global approach, we show that, contrary to the published results, the energetic limits always differ from zero if the physical constraints are correctly expressed. xml:lang="fr" Cependant, les réponses ne sont pas toujours satisfaisantes, particulièrement dans le cas de canaux variants dans le temps. Après une rapide présentation des notions d'énergie limite d'une radiocommunication, et en commençant par une approche globale du problème, nous montrons que, contrairement aux résultats publiés, les limites énergétiques sont toujours différentes de zéro si les contraintes physiques sont correctement exprimées.

  12. Solar system radio emissions studies with the largest low-frequency radio telescopes

    Science.gov (United States)

    Zakharenko, V.; Konovalenko, A.; Litvinenko, G.; Kolyadin, V.; Zarka, P.; Mylostna, K.; Vasylieva, I.; Griessmeier, J.-M.; Sidorchuk, M.; Rucker, H.; Fischer, G.; Cecconi, B.; Coffre, A.; Denis, L.; Shevchenko, V.; Nikolaenko, V.

    2014-04-01

    We describe the trends and tasks in the field of lowfrequency studies of radio emission from the Solar system's objects. The world's largest decameter radio telescopes UTR-2 and URAN have a unique combination of sensitivity and time/frequency resolution parameters, providing the capability of the most detailed studies of various types of solar and planetary emissions.

  13. DSN radio science system description and requirements. [for satellite radio astronomy experiments

    Science.gov (United States)

    Mulhall, B. D. L.

    1977-01-01

    The data system created to collect the functions performed by the Deep Space Network in support of spacecraft radio science experiments is described. Some of the major functional requirements presently being considered for the system are delineated.

  14. DSN radio science system description and requirements. [for satellite radio astronomy experiments

    Science.gov (United States)

    Mulhall, B. D. L.

    1977-01-01

    The data system created to collect the functions performed by the Deep Space Network in support of spacecraft radio science experiments is described. Some of the major functional requirements presently being considered for the system are delineated.

  15. Space Telecommunications Radio System (STRS) Compliance Testing

    Science.gov (United States)

    Handler, Louis M.

    2011-01-01

    The Space Telecommunications Radio System (STRS) defines an open architecture for software defined radios. This document describes the testing methodology to aid in determining the degree of compliance to the STRS architecture. Non-compliances are reported to the software and hardware developers as well as the NASA project manager so that any non-compliances may be fixed or waivers issued. Since the software developers may be divided into those that provide the operating environment including the operating system and STRS infrastructure (OE) and those that supply the waveform applications, the tests are divided accordingly. The static tests are also divided by the availability of an automated tool that determines whether the source code and configuration files contain the appropriate items. Thus, there are six separate step-by-step test procedures described as well as the corresponding requirements that they test. The six types of STRS compliance tests are: STRS application automated testing, STRS infrastructure automated testing, STRS infrastructure testing by compiling WFCCN with the infrastructure, STRS configuration file testing, STRS application manual code testing, and STRS infrastructure manual code testing. Examples of the input and output of the scripts are shown in the appendices as well as more specific information about what to configure and test in WFCCN for non-compliance. In addition, each STRS requirement is listed and the type of testing briefly described. Attached is also a set of guidelines on what to look for in addition to the requirements to aid in the document review process.

  16. Propagation Impact on Modern HF (High Frequency) Communications System Design

    Science.gov (United States)

    1986-03-01

    US Gvt Printing Office, Washington DC. Piggot, W.R., Rawer, K. (1972). URSI Handbook for lonogram Interpretation and... Handbook ", Communications Research Centre Report No. 1255, 1974. Widrow B., Mantey P.E., Griffiths L.J. and Goode B.B., "Adaptive Antenna Systems...implemented in modified form by the terminal node controller (TNC). In the U.S., Amateur Radio Relay League ( ARRL ) radio amateurs have held four annual

  17. Contribution Towards Practical Cognitive Radios Systems

    KAUST Repository

    Ben Ghorbel, Mahdi

    2013-07-01

    Cognitive radios is one of the hot topics for emerging and future wireless commu- nication. It has been proposed as a suitable solution for the spectrum scarcity caused by the increase in frequency demand. The concept is based on allowing unlicensed users, called cognitive or secondary users, to share the unoccupied frequency bands with their owners, called the primary users, under constraints on the interference they cause to them. The objective of our work is to propose some enhancements to cognitive radio systems while taking into account practical constraints. Cogni- tive radios requires a capability to detect spectrum holes (spectrum sensing) and a scheduling flexibility to avoid the occupied spectrum and selectively use the empty spectrum (dynamic resource allocation). Thus, the work is composed of two main parts. The first part focuses on cooperative spectrum sensing. We compute in this part the analytical performance of cooperative spectrum sensing under non identical and imperfect channels. Different schemes are considered for the cooperation between users such as hard binary, censored information, quantized, and soft information. The second part focuses on the dynamic resource allocation. We first propose low-cost re- source allocation algorithms that use location information to estimate the interference to primary users to replace absence of instantaneous channel state information. We extend these algorithms to handle practical implementation constraints such as dis- 5 crete bit-loading and collocated subcarriers allocations. We then propose a reduced dimension approach based on the grouping of subcarriers into clusters and performing the resource allocation over clusters of subcarriers instead of single subcarriers. This approach is shown to reduce the computational complexity of the algorithm with lim- ited performance loss. In addition, it is valid for a generic set of resource allocation problems in presence of co-channel interference between users.

  18. Estimation of Potential Interference Immunity of Radio Reception with Spatial Signal Processing in Mutipath Radio-Communication Channels. Part II. Meter and Decimeter Ranges

    Science.gov (United States)

    Lvov, A. V.; Metelev, S. L.

    2016-11-01

    We propose simulation models for estimating the interference immunity of radio reception using the spatial processing of signals in the airborne and ground-based communication channels of the meter and decimeter wavelength ranges. The ultimate achievable interference immunity under various radio-wave propagation conditions is studied.

  19. Cooperative device-to-device communication in cognitive radio cellular networks

    CERN Document Server

    Li, Peng

    2014-01-01

    This brief examines current research on cooperative device-to-device (D2D) communication as an enhanced offloading technology to improve the performance of cognitive radio cellular networks. By providing an extensive review of recent advances in D2D communication, the authors demonstrate that the quality of D2D links significantly affects offloading performance in cellular networks, which motivates the design of cooperative D2D communication. After presenting the architecture of cooperative D2D communication, the challenges of capacity maximization and energy efficiency are addressed by optimi

  20. Fake BTS Attacks of GSM System on Software Radio Platform

    Directory of Open Access Journals (Sweden)

    Yubo Song

    2012-02-01

    Full Text Available The 2G GSM communication system only provides one-way authentication mechanism which just authenticate the identities of mobile users. As we know, this is not resistant to fake BTS attack. But for the huge cost for building a fake BTS before, this kind of attack were not really implemented before. This paper presents an implement of fake BTS based on software radio technologies. Furthermore, this paper discusses two types of fake BTS attacks on our software radio platform. The first attack is IMSI/IMEI catch attack, which can get the mobile phone’s IMSI and IMEI. With this information, attacker can got the track of the man with this phone. The second attack is selective jamming attack. After get the IMSI and IMEI of the mobile phone, the attackers can decide whether the mobile phone is blocked or not. We will analyze the GSM protocol which is relevant to the interception system and later present the performance of such a system by real tests and demonstrate its feasibility.

  1. Time-Delay Estimation in Dispersed Spectrum Cognitive Radio Systems

    Directory of Open Access Journals (Sweden)

    Celebi Hasari

    2010-01-01

    Full Text Available Time-delay estimation is studied for cognitive radio systems, which facilitate opportunistic use of spectral resources. A two-step approach is proposed to obtain accurate time-delay estimates of signals that occupy multiple dispersed bands simultaneously, with significantly lower computational complexity than the optimal maximum likelihood (ML estimator. In the first step of the proposed approach, an ML estimator is used for each band of the signal in order to estimate the unknown parameters of the signal occupying that band. Then, in the second step, the estimates from the first step are combined in various ways in order to obtain the final time-delay estimate. The combining techniques that are used in the second step are called optimal combining, signal-to-noise ratio (SNR combining, selection combining, and equal combining. It is shown that the performance of the optimal combining technique gets very close to the Cramer-Rao lower bound at high SNRs. These combining techniques provide various mechanisms for diversity combining for time-delay estimation and extend the concept of diversity in communications systems to the time-delay estimation problem in cognitive radio systems. Simulation results are presented to evaluate the performance of the proposed estimators and to verify the theoretical analysis.

  2. A Proposed Model for Radio Frequency Systems to Tracking Trains via GPS(The Study for Egyptian National Railways)

    OpenAIRE

    Hossam Abdel Rahman Mohamed

    2014-01-01

    The Technological evolution which occurred in digital systems favored the appearance of new services to be applied in railways. Radio communications played an important role in the management, exploration, and maintenance of railway transports. Due to the vital importance of security, the track-to-train communications system is studied in depth, with significant changes through the integration in its operation of the global system for mobile communication and global positioning systems. This...

  3. A History of Radio Communications in the Baltimore District

    Science.gov (United States)

    1974-09-30

    K3AKN AA3AKN WAYNE L. LEITER THOMPSONTOWN, PA. Wayne has been a licensed amateur since 1957 and a member of the Susquehanna Emergency Net since...1959. He is shown here with his radio equipment including a Heathkit m\\1-l2 transceiver, which he uses on the net. Since Wayne retired, he finds...WA3GUB BAeD BALTIMORE COUNTY CIVIL DEFENSE TOWSON , MD. I BALTI110RE COUNTY CD HEADQUARTERS, Towson , Maryland J. Alan Nollmeyer, W3YVQ, RACES

  4. Redes de participación e intercambios en la radio pública: los podcasting Networks of Participation and Communicative Interchanges in Public Radio: Podcasting

    Directory of Open Access Journals (Sweden)

    Carmen Salgado Santamaría

    2009-10-01

    Full Text Available El desarrollo de los podcasting, como sistema añadido de la ciberradio, impulsa a las redes de participación e intercambios comunicativos de interés social, que exhiben numerosas ventajas frente a las prácticas radiofónicas conocidas. La difusión que la radio pública realiza de los podcasts, la colocan en el actual proceso de convergencia tecnológica, y la sitúan en una sociedad de la información y del conocimiento, capaz de ofrecer diferentes servicios al alcance de todos los ciudadanos. Sólo la introducción de nuevos contenidos y servicios que aporten valor añadido a los existentes y satisfagan las necesidades de sus usuarios, procurarán la rentabilidad de este sistema. The development of podcasting as an additional system of cyberradio stimulates the appearance of networks of participation and communicative interchanges of social interest, and has numerous advantages over conventional radio practices. The spreading of podcasts through public radio situates it within the process of technological convergence and in an Information and Knowledge society which is able to offer different services within reach of all citizens. Only the introduction of new contents and services that contribute added value to the existing ones and satisfy the needs of users will make this system profitable.

  5. The reach and effect of radio communication campaigns on condom use in Malawi.

    Science.gov (United States)

    Meekers, Dominique; Van Rossem, Ronan; Silva, Martha; Koleros, Andrew

    2007-06-01

    This study uses data from the 2004 Malawi Demographic and Health Survey to assess the reach of selected radio programs about family planning and health in Malawi and their effect on condom use and discussion of family planning. The results show that such radio programs in Malawi reach a broad audience: eight of the 12 programs were heard by at least half of the respondents, although women were less effectively reached than men. For both women and men, the radio programs were found to have a significant impact on family planning discussion with one's partner. The programs' effect on condom use was limited, however. A positive association was found with ever use of condoms, but no association was found with condom use at last intercourse. This limited impact suggests that such radio communication campaigns need to be informed by research identifying the specific constraints to current condom use in Malawi.

  6. Personal communication networks and the effects of an entertainment-education radio soap opera in Tanzania.

    Science.gov (United States)

    Mohammed, S

    2001-01-01

    The personal networks of listeners and nonlisteners to an entertainment-education radio soap opera in Tanzania are examined to determine the effects of interpersonal discussion of the soap opera's educational themes of family planning and HIV prevention. Listeners are more likely to discuss these two educational issues in their personal communication networks and are also more likely to have other listeners to the radio program in their personal communication networks. Respondents demonstrate a relatively high degree of homophily with their network partners and are more likely to discuss matters arising from the radio program with their network partners who are of similar tribal membership, religious affiliation, and gender, and those who are equally or more highly educated than themselves.

  7. Impact of Line Width and Power of Laser on Radio over Fiber System

    Science.gov (United States)

    Sharma, Sakshi; Bhatia, Kamaljeet Singh; Kaur, Harsimrat

    2015-03-01

    In order to increase the capacity of the existing optical communication networks advanced modulation schemes are utilized. Keeping this in view, an radio-over-fiber subcarrier multiplexing (SCM) employing ASK modulation technique is proposed. Response of the system is analysed by varying the linewidth and the power of the CW Laser and the optimum value is concluded for the same so as to achieve reliable communication.

  8. Digital and analog communication systems

    Science.gov (United States)

    Shanmugam, K. S.

    1979-01-01

    The book presents an introductory treatment of digital and analog communication systems with emphasis on digital systems. Attention is given to the following topics: systems and signal analysis, random signal theory, information and channel capacity, baseband data transmission, analog signal transmission, noise in analog communication systems, digital carrier modulation schemes, error control coding, and the digital transmission of analog signals.

  9. Is the current level of training in the use of equipment for prehospital radio communication sufficient?

    DEFF Research Database (Denmark)

    Holm, Jimmy Højberg

    2017-01-01

    BACKGROUND: Physicians working in prehospital care are expected to handle radio communication both within their own sector as well as with other divisions of the National Emergency Services. To date, no study has been conducted on the level of training received by physicians in the use of the equ......BACKGROUND: Physicians working in prehospital care are expected to handle radio communication both within their own sector as well as with other divisions of the National Emergency Services. To date, no study has been conducted on the level of training received by physicians in the use...... of the equipment provided or on the level of competency acquired by physicians. METHODS: In order to investigate the self-assessed skill level acquired in the use of the TETRA (TErrestrial Trunked RAdio) authority radio for communication in a prehospital setting, a cross-sectional study was conducted...... setting 38% of physicians reported having received no training in the use of the equipment, while 80% of physicians reported having received one1 hour of training or less. Among the majority of physicians their current level of training was sufficient for their everyday needs for prehospital communication...

  10. Eleanor Roosevelt, the United Nations and the Role of Radio Communications

    NARCIS (Netherlands)

    Luscombe, Anya

    Eleanor Roosevelt communicated with the public through a variety of media, both before, during and following her time in the White House. In 1946 she became part of the US delegation to the newly formed United Nations and she used newspaper columns, speeches and radio broadcasts to converse with

  11. Eleanor Roosevelt, the United Nations and the Role of Radio Communications

    NARCIS (Netherlands)

    Luscombe, Anya

    2016-01-01

    Eleanor Roosevelt communicated with the public through a variety of media, both before, during and following her time in the White House. In 1946 she became part of the US delegation to the newly formed United Nations and she used newspaper columns, speeches and radio broadcasts to converse with cit

  12. Control and Non-Payload Communications (CNPC) Prototype Radio - Generation 2 Security Flight Test Report

    Science.gov (United States)

    Iannicca, Dennis C.; Ishac, Joseph A.; Shalkhauser, Kurt A.

    2015-01-01

    NASA Glenn Research Center (GRC), in cooperation with Rockwell Collins, is working to develop a prototype Control and Non-Payload Communications (CNPC) radio platform as part of NASA Integrated Systems Research Program's (ISRP) Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) project. A primary focus of the project is to work with the Federal Aviation Administration (FAA) and industry standards bodies to build and demonstrate a safe, secure, and efficient CNPC architecture that can be used by industry to evaluate the feasibility of deploying a system using these technologies in an operational capacity. GRC has been working in conjunction with these groups to assess threats, identify security requirements, and to develop a system of standards-based security controls that can be applied to the GRC prototype CNPC architecture as a demonstration platform. The proposed security controls were integrated into the GRC flight test system aboard our S-3B Viking surrogate aircraft and several network tests were conducted during a flight on November 15th, 2014 to determine whether the controls were working properly within the flight environment. The flight test was also the first to integrate Robust Header Compression (ROHC) as a means of reducing the additional overhead introduced by the security controls and Mobile IPv6. The effort demonstrated the complete end-to-end secure CNPC link in a relevant flight environment.

  13. UAS in the NAS Project: Large-Scale Communication Architecture Simulations with NASA GRC Gen5 Radio Model

    Science.gov (United States)

    Kubat, Gregory

    2016-01-01

    This report provides a description and performance characterization of the large-scale, Relay architecture, UAS communications simulation capability developed for the NASA GRC, UAS in the NAS Project. The system uses a validated model of the GRC Gen5 CNPC, Flight-Test Radio model. Contained in the report is a description of the simulation system and its model components, recent changes made to the system to improve performance, descriptions and objectives of sample simulations used for test and verification, and a sampling and observations of results and performance data.

  14. White House Communications Agency (WHCA) Presidential Voice Communications Rack Mount System Mechanical Drawing Package

    Science.gov (United States)

    2015-12-01

    Harris , 117G, communications, White House Communications Agency 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18...used by WHCA. The customer desired to upgrade their comms equipment from Harris 117F radios to 117G radios. These radios offer a smaller package with...rack unit (9U) chassis that did not use a fiber optic modem and instead used direct radio frequency (RF) output from the Harris 117F radio. The

  15. Cooperative cognitive radio networking system model, enabling techniques, and performance

    CERN Document Server

    Cao, Bin; Mark, Jon W

    2016-01-01

    This SpringerBrief examines the active cooperation between users of Cooperative Cognitive Radio Networking (CCRN), exploring the system model, enabling techniques, and performance. The brief provides a systematic study on active cooperation between primary users and secondary users, i.e., (CCRN), followed by the discussions on research issues and challenges in designing spectrum-energy efficient CCRN. As an effort to shed light on the design of spectrum-energy efficient CCRN, they model the CCRN based on orthogonal modulation and orthogonally dual-polarized antenna (ODPA). The resource allocation issues are detailed with respect to both models, in terms of problem formulation, solution approach, and numerical results. Finally, the optimal communication strategies for both primary and secondary users to achieve spectrum-energy efficient CCRN are analyzed.

  16. COMMUNICATIONS AND INFORMATION SYSTEMS

    Directory of Open Access Journals (Sweden)

    Dănuţ ŢIGĂNUŞ

    2011-01-01

    Full Text Available This essay assesses the communications and information systems (CIS in support of the civilian and military structures deployed in the European Union led crises management operations and missions. The article emphasizes the specific structure and function of CIS taking in consideration the particularities of EU led missions. The integration of the EU institutional networks and systems with the national systems provided by the EU member states is considered a key element. The analysis-part of this paper starts with the specific EU command and control system for crises management missions based on two autonomous solutions and one relying on NATO capabilities. Further, it continues with the challenges of the classifi ed information exchange at the operational theatre level. The most important contribution of this article is based on the long term vision implementation measures for the CIS structure, roles, functions and services provided and the information management infrastructure. CIS deployment mechanisms are described with references to the practical situation of the CIS deployed in support of crises management operations and missions. Two important defi nitions are provided regarding the CIS for crisis management and their roles in the specific EU operational environment. The system view of the operational CIS is depicted and analysed also, with a focus on the integration aspects of the infrastructure as the information transport layer for the information exchange flow. The last part of the article focuses on the CIS functions for the deployed systems which are detailed alongside with the C2 and Information Exchange Requirements in the EU operational environment. The variety of the theoretical approaches to determine the CIS infrastructure for EU-led civilian and military missions triggers the conclusion that the planning and implementation process is extremely complex especially in the context of the new security environment and requires

  17. Introduction to digital communication systems

    CERN Document Server

    Wesolowski, Krzysztof

    2009-01-01

    Combining theoretical knowledge and practical applications, this advanced-level textbook covers the most important aspects of contemporary digital communication systems. Introduction to Digital Communication Systems focuses on the rules of functioning digital communication system blocks, starting with the performance limits set by the information theory. Drawing on information relating to turbo codes and LDPC codes, the text presents the basic methods of error correction and detection, followed by baseband transmission methods, and single- and multi-carrier digital modulations. The basi

  18. Satellite augmentation of cellular type mobile radio telephone systems

    Science.gov (United States)

    Anderson, Roy E.

    NASA's ATS-6 satellite relayed voice bandwidth communications between five trucks and the trucking company dispatchers as the trucks traveled throughout the north-eastern quarter of the contiguous United States. The experiment, conducted over a seven month period, demonstrated that propagation characteristics are much different for the satellite-mobile links than for terrestrial-mobile links. A properly designed satellite system can provide high quality, reliable voice and data communications except where the vehicle-satellite path is shadowed by a structure or terrain feature. Mobile equipment in the experiment was adapted from commercial mobile radios. The vehicle antennas were 75 cm tall, 2 cm diam. Another experiment proved the feasibility of vehicle position surveillance using active two-way tone-code ranging through ATS-6 to provide one line of position and passive one-way ranging by measuring the time-of-arrival of a signal from an independent satellite. A position fix was printed out at an earth station 1 sec after it sent the interrogation signal to the distant vehicle, a towboat on the Mississippi River. The line of position from ATS-6 was accurate to 0.1 nautical mile using a voice bandwidth ranging signal. The line of position from the NOAA GOES satellite was accurate to 2 miles, using 100 Hz signal bandwidth. If the signal from the independent satellite had the same bandwidth and signal-to-noise ratio as ATS-6, the fixes would have been accurate to about 0.1 nautical mile. A concept study concluded that satellites might be a cost effective augmentation of terrestrial cellular type mobile radio telephone systems. The satellites would serve thinly populated areas where terrestrial systems are not cost effective. In the United States, the satellites would serve about 90% of the land area where 20% of the population resides. A multibeam satellite with many channels in each beam would be compatible with the urban terrestrial systems and together they would

  19. Mobile radio alternative systems study satellite/terrestrial (hybrid) systems concepts

    Science.gov (United States)

    Kiesling, J. D.; Anderson, R. E.

    1983-01-01

    The use of satellites for mobile radio service in non-urban areas of the United States in the years from 1985 to 2000 was investigated. Several satellite concepts are considered: a system with single-beam coverage of the fifty United States and Puerto Rico, and multi-beam satellites with greater capacity. All of the needed functions and services identified in the market study are provided by the satellite systems, including nationwide radio access to vehicles without knowledge of vehicle location wideband data transmission from remote sites, two way exchange of short data and control messages between vehicles and dispatch or control centers, and automatic vehicle location (surveillance). The costs of providing the services are within acceptable limits, and the desired returns to the system investors are attractive. The criteria by which the Federal Communication judges the competing demands for public radio spectrum are reviewed with comments on how the criteria might apply to the consideration of land mobile satellites. Institutional arrangements for operating a mobile satellite system are based on the present institutional arrangements in which the services are offered to the end users through wireline and radio common carriers, with direct access by large private and government users.

  20. Research on communication system of underground safety management based on leaky feeder cable

    Institute of Scientific and Technical Information of China (English)

    CHEN Jian-hong; ZHANG Tao; CHENG Yun-cai; ZHANG Han

    2007-01-01

    According to the current working status of underground safety management and production scheduling, the importance and existed problem of underground mine radio communication were summarized, and the basic principle and classification of leaky feeder cable were introduced and the characteristics of cable were analyzed specifically in depth, and the application model of radio communication system for underground mine safety management was put forward. Meanwhile, the research explanation of the system component, function and evaluation was provided. The discussion result indicates that communication system of underground mine safety management which is integrated two-way relay amplifier and other equipment has many communication functions, and underground mine mobile communication can be achieved well.

  1. Opportunistic Communication (Cognitive Radio over Primary Discarded Subchannels by Applying a Double Power Distribution

    Directory of Open Access Journals (Sweden)

    G. A. Medina-Acosta

    2010-01-01

    Full Text Available This paper proposes the establishment of a simultaneous cognitive radio communication based on a subdistribution of power made over unselected subchannels which were discarded by the primary user through an initial optimal power allotment. The aim of this work is to show the possibility of introducing an opportunistic communication into a licensed transmission where the total power constraint is shared. The analysis of the proposed transmission scheme was performed by considering 128 and 2048 independent subchannels affected by Rayleigh fading, over 10,000 channel realizations, and three different signal-to-noise ratios (8 dB, 16 dB, and 24 dB. From the system evaluation it was possible to find the optimal power allotment for the primary user, the subdistribution of power for the secondary user, as well as the attenuation and the capacity per subchannel for every channel realization. Moreover, the PDF and CDF of the total obtained capacities, as well as the generation of empirical capacity regions, were estimated as complementary results.

  2. Enhanced cognitive Radio Resource Management for LTE systems

    KAUST Repository

    Alqerm, Ismail

    2013-10-01

    The explosive growth in mobile Internet and related services has increased the need for more bandwidth in cellular networks. The Long-Term Evolution (LTE) technology is an attractive solution for operators and subscribers to meet such need since it provides high data rates and scalable bandwidth. Radio Resource Management (RRM) is essential for LTE to provide better communication quality and meet the application QoS requirements. Cognitive resource management is a promising solution for LTE RRM as it improves network efficiency by exploiting radio environment information, intelligent optimization algorithms to configure transmission parameters, and mitigate interference. In this paper, we propose a cognitive resource management scheme to adapt LTE network parameters to the environment conditions. The scheme optimizes resource blocks assignment, modulation selection and bandwidth selection to maximize throughput and minimize interference. The scheme uses constrained optimization for throughput maximization and interference control. It is also enhanced by learning mechanism to reduce the optimization complexity and improve the decision-making quality. Our evaluation results show that our scheme achieved significant improvements in throughput and LTE system capacity. Results also show the improvement in the user satisfaction over other techniques in LTE RRM.

  3. Applications of Microwave Photonics in Radio Astronomy and Space Communication

    Science.gov (United States)

    D'Addario, Larry R.; Shillue, William P.

    2006-01-01

    An overview of narrow band vs wide band signals is given. Topics discussed included signal transmission, reference distribution and photonic antenna metrology. Examples of VLA, ALMA, ATA and DSN arrays are given. . Arrays of small antennas have become more cost-effective than large antennas for achieving large total aperture or gain, both for astronomy and for communication. It is concluded that emerging applications involving arrays of many antennas require low-cost optical communication of both wide bandwidth and narrow bandwidth; development of round-trip correction schemes enables timing precision; and free-space laser beams with microwave modulation allow structural metrology with approx 100 micrometer precision over distances of 200 meters.

  4. A Study and Design of a Configurable CDMA Communication Platform

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ Software radio.Software radio, together with digital radio as its basis, has been the trends to development in wireless communications. Digital radio focuses on all-digitalization techniques and modularization methods in communication systems, while software radio pays more attention to all-digialtized radio's software structure and opening architecture.

  5. Wavelet transform domain communication systems

    Science.gov (United States)

    Orr, Richard S.; Pike, Cameron; Lyall, Michael J.

    1995-04-01

    In this paper we introduce a new class of communications systems called wavelet transform domain (WTD) systems. WTD systems are transmultiplexer (TMUX) structures in which information to be communicated over a channel is encoded, via an inverse discrete wavelet transform (IDWT), as the wavelet coefficients of the transmitted signal, and extracted at the receiver by a discrete wavelet transform (DWT). WTD constructs can be used for covert, or low probability of intercept/detection (LPI/D) communications, baseband bandwidth efficient communications, or code-division multiple access (CDMA). This paper concentrates on the spread spectrum applications.

  6. The Sandblaster Software-Defined Radio Platform for Mobile 4G Wireless Communications

    Directory of Open Access Journals (Sweden)

    V. Surducan

    2009-01-01

    Full Text Available We present a tier 2 Software Defined-Radio platform (SDR, built around the latest Sandbridge Technologies' multithreaded Digital Signal Processor (DSP SB3500, along with the description of major design steps taken to ensure the best radio link and computational performance. This SDR platform is capable of executing 4G wireless communication standards such as WiMAX Wave 2, WLAN 802.11 g, and LTE. Performance results for WiMAX are presented in the conclusion section.

  7. Survey of Green Radio Communications Networks: Techniques and Recent Advances

    Directory of Open Access Journals (Sweden)

    Mohammed H. Alsharif

    2013-01-01

    Full Text Available Energy efficiency in cellular networks has received significant attention from both academia and industry because of the importance of reducing the operational expenditures and maintaining the profitability of cellular networks, in addition to making these networks “greener.” Because the base station is the primary energy consumer in the network, efforts have been made to study base station energy consumption and to find ways to improve energy efficiency. In this paper, we present a brief review of the techniques that have been used recently to improve energy efficiency, such as energy-efficient power amplifier techniques, time-domain techniques, cell switching, management of the physical layer through multiple-input multiple-output (MIMO management, heterogeneous network architectures based on Micro-Pico-Femtocells, cell zooming, and relay techniques. In addition, this paper discusses the advantages and disadvantages of each technique to contribute to a better understanding of each of the techniques and thereby offer clear insights to researchers about how to choose the best ways to reduce energy consumption in future green radio networks.

  8. Radio propagation and adaptive antennas for wireless communication networks

    CERN Document Server

    Blaunstein, Nathan

    2014-01-01

    Explores novel wireless networks beyond 3G, and advanced 4G technologies, such as MIMO, via propagation phenomena and the fundamentals of adapted antenna usage.Explains how adaptive antennas can improve GoS and QoS for any wireless channel, with specific examples and applications in land, aircraft and satellite communications.Introduces new stochastic approach based on several multi-parametric models describing various terrestrial scenarios, which have been experimentally verified in different environmental conditionsNew chapters on fundamentals of wireless networks, cellular and non-cellular,

  9. Communications device identification methods, communications methods, wireless communications readers, wireless communications systems, and articles of manufacture

    Science.gov (United States)

    Steele, Kerry D [Kennewick, WA; Anderson, Gordon A [Benton City, WA; Gilbert, Ronald W [Morgan Hill, CA

    2011-02-01

    Communications device identification methods, communications methods, wireless communications readers, wireless communications systems, and articles of manufacture are described. In one aspect, a communications device identification method includes providing identification information regarding a group of wireless identification devices within a wireless communications range of a reader, using the provided identification information, selecting one of a plurality of different search procedures for identifying unidentified ones of the wireless identification devices within the wireless communications range, and identifying at least some of the unidentified ones of the wireless identification devices using the selected one of the search procedures.

  10. VibeComm: radio-free wireless communication for smart devices using vibration.

    Science.gov (United States)

    Hwang, Inhwan; Cho, Jungchan; Oh, Songhwai

    2014-11-10

    This paper proposes VibeComm, a novel communication method for smart devices using a built-in vibrator and accelerometer. The proposed approach is ideal for low-rate off-line communication, and its communication medium is an object on which smart devices are placed, such as tables and desks. When more than two smart devices are placed on an object and one device wants to transmit a message to the other devices, the transmitting device generates a sequence of vibrations. The vibrations are propagated through the object on which the devices are placed. The receiving devices analyze their accelerometer readings to decode incoming messages. The proposed method can be the alternative communication method when general types of radio communication methods are not available. VibeComm is implemented on Android smartphones, and a comprehensive set of experiments is conducted to show its feasibility.

  11. VibeComm: Radio-Free Wireless Communication for Smart Devices Using Vibration

    Directory of Open Access Journals (Sweden)

    Inhwan Hwang

    2014-11-01

    Full Text Available This paper proposes VibeComm, a novel communication method for smart devices using a built-in vibrator and accelerometer. The proposed approach is ideal for low-rate off-line communication, and its communication medium is an object on which smart devices are placed, such as tables and desks. When more than two smart devices are placed on an object and one device wants to transmit a message to the other devices, the transmitting device generates a sequence of vibrations. The vibrations are propagated through the object on which the devices are placed. The receiving devices analyze their accelerometer readings to decode incoming messages. The proposed method can be the alternative communication method when general types of radio communication methods are not available. VibeComm is implemented on Android smartphones, and a comprehensive set of experiments is conducted to show its feasibility.

  12. Jitter-Robust Orthogonal Hermite Pulses for Ultra-Wideband Impulse Radio Communications

    Directory of Open Access Journals (Sweden)

    Ryuji Kohno

    2005-03-01

    Full Text Available The design of a class of jitter-robust, Hermite polynomial-based, orthogonal pulses for ultra-wideband impulse radio (UWB-IR communications systems is presented. A unified and exact closed-form expression of the auto- and cross-correlation functions of Hermite pulses is provided. Under the assumption that jitter values are sufficiently smaller than pulse widths, this formula is used to decompose jitter-shifted pulses over an orthonormal basis of the Hermite space. For any given jitter probability density function (pdf, the decomposition yields an equivalent distribution of N-by-N matrices which simplifies the convolutional jitter channel model onto a multiplicative matrix model. The design of jitter-robust orthogonal pulses is then transformed into a generalized eigendecomposition problem whose solution is obtained with a Jacobi-like simultaneous diagonalization algorithm applied over a subset of samples of the channel matrix distribution. Examples of the waveforms obtained with the proposed design and their improved auto- and cross-correlation functions are given. Simulation results are presented, which demonstrate the superior performance of a pulse-shape modulated (PSM- UWB-IR system using the proposed pulses, over the same system using conventional orthogonal Hermite pulses, in jitter channels with additive white Gaussian noise (AWGN.

  13. MEMS-based Circuits and Systems for Wireless Communication

    CERN Document Server

    Kaiser, Andreas

    2013-01-01

    MEMS-based Circuits and Systems for Wireless Communication provides comprehensive coverage of RF-MEMS technology from device to system level. This edited volume places emphasis on how system performance for radio frequency applications can be leveraged by Micro-Electro-Mechanical Systems (MEMS). Coverage also extends to innovative MEMS-aware radio architectures that push the potential of MEMS technology further ahead.  This work presents a broad overview of the technology from MEMS devices (mainly BAW and Si MEMS resonators) to basic circuits, such as oscillators and filters, and finally complete systems such as ultra-low-power MEMS-based radios. Contributions from leading experts around the world are organized in three parts. Part I introduces RF-MEMS technology, devices and modeling and includes a prospective outlook on ongoing developments towards Nano-Electro-Mechanical Systems (NEMS) and phononic crystals. Device properties and models are presented in a circuit oriented perspective. Part II focusses on ...

  14. Modeling of Reverberation Effects for Radio Localization and Communications

    DEFF Research Database (Denmark)

    Steinböck, Gerhard

    2013-01-01

    in indoor environments. We show that this component carries a significant portion of the total received power. Thus, the accurate modeling of it is of prime importance for both communication and positioning. To clarify the cause of the diffuse component we first experimentally investigate the spread...... into a distance dependent model of the delay power spectrum, which we then validate experimentally. From this model we derive secondary models that predict the received power, the mean delay, the rms delay spread and the kurtosis versus distance. The behavior of the diffuse component versus distance in indoor...... in the diffuse power due to opening windows, the presence of people or by changing the size of the room. As an example of the benefits of modeling the diffuse component in indoor environments we present a study of the performance of a positioning estimator that jointly utilizes the secondary models of received...

  15. Future Standardization of Space Telecommunications Radio System with Core Flight System

    Science.gov (United States)

    Briones, Janette C.; Hickey, Joseph P.; Roche, Rigoberto; Handler, Louis M.; Hall, Charles S.

    2016-01-01

    NASA Glenn Research Center (GRC) is integrating the NASA Space Telecommunications Radio System (STRS) Standard with the Core Flight System (cFS), an avionics software operating environment. The STRS standard provides a common, consistent framework to develop, qualify, operate and maintain complex, reconfigurable and reprogrammable radio systems. The cFS is a flexible, open architecture that features a plugand- play software executive called the Core Flight Executive (cFE), a reusable library of software components for flight and space missions and an integrated tool suite. Together, STRS and cFS create a development environment that allows for STRS compliant applications to reference the STRS application programmer interfaces (APIs) that use the cFS infrastructure. These APIs are used to standardize the communication protocols on NASAs space SDRs. The cFS-STRS Operating Environment (OE) is a portable cFS library, which adds the ability to run STRS applications on existing cFS platforms. The purpose of this paper is to discuss the cFS-STRS OE prototype, preliminary experimental results performed using the Advanced Space Radio Platform (ASRP), the GRC S- band Ground Station and the SCaN (Space Communication and Navigation) Testbed currently flying onboard the International Space Station (ISS). Additionally, this paper presents a demonstration of the Consultative Committee for Space Data Systems (CCSDS) Spacecraft Onboard Interface Services (SOIS) using electronic data sheets (EDS) inside cFE. This configuration allows for the data sheets to specify binary formats for data exchange between STRS applications. The integration of STRS with cFS leverages mission-proven platform functions and mitigates barriers to integration with future missions. This reduces flight software development time and the costs of software-defined radio (SDR) platforms. Furthermore, the combined benefits of STRS standardization with the flexibility of cFS provide an effective, reliable and

  16. Radio propagation measurement and channel modelling

    CERN Document Server

    Salous, Sana

    2013-01-01

    While there are numerous books describing modern wireless communication systems that contain overviews of radio propagation and radio channel modelling, there are none that contain detailed information on the design, implementation and calibration of radio channel measurement equipment, the planning of experiments and the in depth analysis of measured data. The book would begin with an explanation of the fundamentals of radio wave propagation and progress through a series of topics, including the measurement of radio channel characteristics, radio channel sounders, measurement strategies

  17. Design, Development and Pre-Flight Testing of the Communications, Navigation, and Networking Reconfigurable Testbed (Connect) to Investigate Software Defined Radio Architecture on the International Space Station

    Science.gov (United States)

    Over, Ann P.; Barrett, Michael J.; Reinhart, Richard C.; Free, James M.; Cikanek, Harry A., III

    2011-01-01

    The Communication Navigation and Networking Reconfigurable Testbed (CoNNeCT) is a NASA-sponsored mission, which will investigate the usage of Software Defined Radios (SDRs) as a multi-function communication system for space missions. A softwaredefined radio system is a communication system in which typical components of the system (e.g., modulators) are incorporated into software. The software-defined capability allows flexibility and experimentation in different modulation, coding and other parameters to understand their effects on performance. This flexibility builds inherent redundancy and flexibility into the system for improved operational efficiency, real-time changes to space missions and enhanced reliability/redundancy. The CoNNeCT Project is a collaboration between industrial radio providers and NASA. The industrial radio providers are providing the SDRs and NASA is designing, building and testing the entire flight system. The flight system will be integrated on the Express Logistics Carrier (ELC) on the International Space Station (ISS) after launch on the H-IIB Transfer Vehicle in 2012. This paper provides an overview of the technology research objectives, payload description, design challenges and pre-flight testing results.

  18. Underwater wireless communication system

    Energy Technology Data Exchange (ETDEWEB)

    Goh, J H; Shaw, A; Al-Shamma' a, A I, E-mail: j.h.goh@2006.ljmu.ac.u [Liverpool John Moores University, General Engineering Research Institute (GERI), RF and Microwave Group, Byrom Street, Liverpool, L3 3AF (United Kingdom)

    2009-07-01

    Underwater communication has a range of applications including remotely operated vehicle (ROV) and autonomous underwater vehicle (AUV) communication and docking in the offshore industry. Current underwater transmission techniques is primarily utilise sound waves for large distance at lower frequencies and the velocity of sound in water is approximately 1500m/s the resultant communications have problems with multi-path propagation and low bandwidth problems. The use of electromagnetic (EM) techniques underwater has largely been overlooked because of the attenuation due to the conductivity of seawater. However, for short range applications, the higher frequencies and much higher velocity can prove advantageous. This paper will outline a project which will utilise recent investigations that demonstrate EM wave propagation up to the MHz frequency range is possible in seawater.

  19. Experimental implant communication of high data rate video using an ultra wideband radio link.

    Science.gov (United States)

    Chávez-Santiago, Raúl; Balasingham, Ilangko; Bergsland, Jacob; Zahid, Wasim; Takizawa, Kenichi; Miura, Ryu; Li, Huan-Bang

    2013-01-01

    Ultra wideband (UWB) is one of the radio technologies adopted by the IEEE 802.15.6™-2012 standard for on-body communication in body area networks (BANs). However, a number of simulation-based studies suggest the feasibility of using UWB for high data rate implant communication too. This paper presents an experimental verification of said predictions. We carried out radio transmissions of H.264/1280×720 pixels video at 80 Mbps through a UWB multiband orthogonal frequency division multiplexing (MB-OFDM) interface in a porcine chirurgical model. The results demonstrated successful transmission up to a maximum depth of 30 mm in the abdomen and 33 mm in the thorax within the 4.2-4.8 GHz frequency band.

  20. Conversion of a 30-m former satellite communications antenna to a radio telescope

    Science.gov (United States)

    Deboer, David R.; Steffes, Paul G.; Glowacki, John M.

    1998-05-01

    A class of large satellite communication antennas built in the mid-1970's comprise a potential set of large antennas available for use by radio astronomers upon upgrade. With the advent of low noise technology these facilities have been superseded in the communications industry by smaller, more manageable facilities. Although many have sat idle and decaying over the intervening years, these facilities remain a potential resource for research and education. A pair of such dishes has been acquired by Georgia Tech and one of the 30 meter antennas has been completely mechanically and electrically stripped and new mechanical, control, RF, and electrical systems installed. The antenna is now driven by four continuous-speed vector-controlled three-phase AC induction motors with variable frequency vector motor drives. Sixteen bit resolution optical absolute position encoders on each axis provide telescope pointing data. Sixteen bit resolution optical absolute position encoders on each axis provide telescope pointing data. A programmable logic controller provides interlock monitoring and control. The antenna is controllable both manually via a portable remote control unit and via a Pentium PC running control software on a real-time UNIX-based platform. The manual unit allows limited control at two user-selectable speeds while computer control allows full tracking capability with accuracies of better than 0.3 arcminutes. The facility can be remotely controlled via the internet, although currently only a dedicated line is used. The antenna has been refitted with an ultra-broadband feed system capable of operating from 1-7 GHz.

  1. On Building Secure Communication Systems

    DEFF Research Database (Denmark)

    Carvalho Quaresma, Jose Nuno

    This thesis presents the Guided System Development (GSD) framework, which aims at supporting the development of secure communication systems. A communication system is specified in a language similar to the Alice and Bob notation, a simple and intuitive language used to describe the global...... perspective of the communications between different principals. The notation used in the GSD framework extends that notation with constructs that allow the security requirements of the messages to be described. From that specification, the developer is guided through a semi-automatic translation that enables...... into code that implements the communication skeleton of the system and can then be used by the system designer. New output languages can also easily be added to the GSD framework. Additionally, a prototype of the GSD framework was implemented and an ex-ample of using the GSD framework in a real world system...

  2. RFID Transponders' RF Emissions in Aircraft Communication and Navigation Radio Bands

    Science.gov (United States)

    Nguyen, Truong X.; Ely, Jay J.; Koppen Sandra V.; Fersch, Mariatheresa S.

    2008-01-01

    Radiated emission data in aircraft communication and navigation bands are presented for several active radio frequency identification (RFID) tags. The individual tags are different in design, operation and transmitting frequencies. The process for measuring the tags emissions in a reverberation chamber is discussed. Measurement issues dealing with tag interrogation, low level measurement in the presence of strong transmissions, and tags low duty factors are discussed. The results show strong emissions, far exceeding aircraft emission limits and can be of potential interference risks.

  3. Communication, Work Systems and HRD

    Science.gov (United States)

    Pace, R. Wayne

    2013-01-01

    Purpose: The purpose of this article is to show the foundational place that communication theory and its practice occupies in functioning work systems. Design/methodology/approach: This paper defines the word communication in terms of the creation and interpretation of displays, describes what it means to have a theoretical foundation for a…

  4. Radio Frequency Microelectromechanical Systems in Defence and Aerospace

    Directory of Open Access Journals (Sweden)

    D.V.K. Sastry

    2009-11-01

    Full Text Available For all onboard systems applications, it is important to have very low-loss characteristics and low power consumption coupled with size reduction. The controls and instrumentation in defence and aerospace continually calls for newer technologies and developments. One such technology showing remarkable potential over the years is radio frequency microelectromechanical systems (RF MEMS which have already made their presence felt prominently by offering replacement in radar and communication systems with high quality factors and precise tunability. The RF MEMS components have emerged as potential candidates for defence and aerospace applications. The core theme of this paper is to drive home the fact that the limitations faced by the current RF devices can be overcome by the flexibility and better device performance characteristics of RF MEMS components, which ultimately propagate the device level benefits to the final system to attain the unprecedented levels of performance.Defence Science Journal, 2009, 59(6, pp.568-567, DOI:http://dx.doi.org/10.14429/dsj.59.1561

  5. Multiantenna systems for MIMO communications

    CERN Document Server

    DeFlaviis, Franco

    2008-01-01

    Advanced communication scenarios demand the development of new systemswhere antenna theory, channel propagation and communication models are seen from a common perspective as a way to understand and optimize the system as a whole. In this context, a comprehensive multiantenna formulation for multiple-input multiple-output systems is presented with a special emphasis on the connection of the electromagnetic and communication principles.Starting from the capacity for amultiantenna system, the book reviews radiation, propagation, and communicationmechanisms, paying particular attention to the vec

  6. AROMA: Automatic Generation of Radio Maps for Localization Systems

    CERN Document Server

    Eleryan, Ahmed; Youssef, Moustafa

    2010-01-01

    WLAN localization has become an active research field recently. Due to the wide WLAN deployment, WLAN localization provides ubiquitous coverage and adds to the value of the wireless network by providing the location of its users without using any additional hardware. However, WLAN localization systems usually require constructing a radio map, which is a major barrier of WLAN localization systems' deployment. The radio map stores information about the signal strength from different signal strength streams at selected locations in the site of interest. Typical construction of a radio map involves measurements and calibrations making it a tedious and time-consuming operation. In this paper, we present the AROMA system that automatically constructs accurate active and passive radio maps for both device-based and device-free WLAN localization systems. AROMA has three main goals: high accuracy, low computational requirements, and minimum user overhead. To achieve high accuracy, AROMA uses 3D ray tracing enhanced wi...

  7. Programmable Logic Device (PLD) Design Description for the Integrated Power, Avionics, and Software (iPAS) Space Telecommunications Radio System (STRS) Radio

    Science.gov (United States)

    Shalkhauser, Mary Jo W.

    2017-01-01

    The Space Telecommunications Radio System (STRS) provides a common, consistent framework for software defined radios (SDRs) to abstract the application software from the radio platform hardware. The STRS standard aims to reduce the cost and risk of using complex, configurable and reprogrammable radio systems across NASA missions. To promote the use of the STRS architecture for future NASA advanced exploration missions, NASA Glenn Research Center (GRC) developed an STRS compliant SDR on a radio platform used by the Advance Exploration System program at the Johnson Space Center (JSC) in their Integrated Power, Avionics, and Software (iPAS) laboratory. At the conclusion of the development, the software and hardware description language (HDL) code was delivered to JSC for their use in their iPAS test bed to get hands-on experience with the STRS standard, and for development of their own STRS Waveforms on the now STRS compliant platform.The iPAS STRS Radio was implemented on the Reconfigurable, Intelligently-Adaptive Communication System (RIACS) platform, currently being used for radio development at JSC. The platform consists of a Xilinx ML605 Virtex-6 FPGA board, an Analog Devices FMCOMMS1-EBZ RF transceiver board, and an Embedded PC (Axiomtek eBox 620-110-FL) running the Ubuntu 12.4 operating system. Figure 1 shows the RIACS platform hardware. The result of this development is a very low cost STRS compliant platform that can be used for waveform developments for multiple applications.The purpose of this document is to describe the design of the HDL code for the FPGA portion of the iPAS STRS Radio particularly the design of the FPGA wrapper and the test waveform.

  8. Control and Non-Payload Communications (CNPC) Prototype Radio - Generation 2 Security Architecture Lab Test Report

    Science.gov (United States)

    Iannicca, Dennis C.; McKim, James H.; Stewart, David H.; Thadhani, Suresh K.; Young, Daniel P.

    2015-01-01

    NASA Glenn Research Center, in cooperation with Rockwell Collins, is working to develop a prototype Control and Non-Payload Communications (CNPC) radio platform as part of NASA Integrated Systems Research Program's (ISRP) Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) project. A primary focus of the project is to work with the FAA and industry standards bodies to build and demonstrate a safe, secure, and efficient CNPC architecture that can be used by industry to evaluate the feasibility of deploying a system using these technologies in an operational capacity. GRC has been working in conjunction with these groups to assess threats, identify security requirements, and to develop a system of standards-based security controls that can be applied to the current GRC prototype CNPC architecture as a demonstration platform. The security controls were integrated into a lab test bed mock-up of the Mobile IPv6 architecture currently being used for NASA flight testing, and a series of network tests were conducted to evaluate the security overhead of the controls compared to the baseline CNPC link without any security. The aim of testing was to evaluate the performance impact of the additional security control overhead when added to the Mobile IPv6 architecture in various modes of operation. The statistics collected included packet captures at points along the path to gauge packet size as the sample data traversed the CNPC network, round trip latency, jitter, and throughput. The effort involved a series of tests of the baseline link, a link with Robust Header Compression (ROHC) and without security controls, a link with security controls and without ROHC, and finally a link with both ROHC and security controls enabled. The effort demonstrated that ROHC is both desirable and necessary to offset the additional expected overhead of applying security controls to the CNPC link.

  9. Interference Aware Optimisation of Throughput in Cognitive Radio System

    Directory of Open Access Journals (Sweden)

    Gaurav Verma

    2015-07-01

    Full Text Available In the cognitive radio (CR system where spectrum sensing and data transmissions are performed simultaneously, the proper selection of frame duration (τ is of utmost importance. Small τ leads to an increased false alarm probability while large value of it delays implementation of sensing decision of the current frame to the next. The former case decreases the achievable throughput of the CR user while latter one may disturb the licensed user communication. Under the constraints of maintaining a target detection probability of dP, this paper attempts to design a frame duration τ where achieved throughput of the CR system is maximised. To do so, an analysis of achievable throughput with τ was performed which reveals that, initially, with the increase in τ, the achievable throughput increases sharply, but after its certain value, the increments are negligible and achievable throughput appears to maintain a constant value. The performed analysis shows that, it is not possible to perfectly optimize τ, however, a close optimisation can still be performed which can maximise the achievable throughput. From the realistic point of view, the CR system is further modelled under uncertain noise conditions. The achieved simulation results well justify the presented analysis.Defence Science Journal, Vol. 65, No. 4, July 2015, pp. 312-318, DOI: http://dx.doi.org/10.14429/dsj.65.8739

  10. Quantum Communication Systems

    Science.gov (United States)

    2008-03-15

    Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39-18 Publications: 1) W. Wasilewski and...K. Banaszek, Protecting an optical qubit against photon loss, Phys. Rev. A 75, 042316 (2007) 2) K. Banaszek and W. Wasilewski , Linear-optics...manipulations of photon-loss codes, Proceedings of NATO Advanced Research Workshop "Quantum Communication and Security" 3) W. Wasilewski , P. Kolenderski

  11. Blind Recognition Algorithm of Turbo Codes for Communication Intelligence Systems

    Directory of Open Access Journals (Sweden)

    Ali Naseri

    2011-11-01

    Full Text Available Turbo codes are widely used in land and space radio communication systems, and because of complexity of structure, are custom in military communication systems. In electronic warfare, COMINT systems make attempt to recognize codes by blind ways. In this Paper, the algorithm is proposed for blind recognition of turbo code parameters like code kind, code-word length, code rate, length of interleaver and delay blocks number of convolution code. The algorithm calculations volume is0.5L3+1.25L, therefore it is suitable for real time systems.

  12. Optimal design of basic pulse waveforms for THSS UWB radio systems

    Institute of Scientific and Technical Information of China (English)

    Jia Lin; Zhang Zhongzhao

    2005-01-01

    Ultrawide bandwidth (UWB) radio, a very promising technique carrying information in very short basic pulses, has properties that make it a viable candidate for short-range wireless communications. In this paper, several short-pulse waveforms based on Gaussian genetic monocycle as well as Gaussian pulse waveform, as candidates of basic UWB pulse waveforms, are firstly proposed and investigated. Their spectrum characteristics, bit transmission rate (BTR), and bit error rate (BER) performance in AWGN channel using time hopping spread spectrum (THSS) and pulse position modulation (PPM) are simulated and evaluated. The numerical results are compared and show that the basic pulse waveforms determine the spectrum characteristics of UWB signals and have much effect on the performance of UWB radio system. The performance of UWB radio system achieved by the proposed basic pulse waveforms is much better than that of UWB radio system realized by other used basic pulse waveforms under the uniform conditions. Also,the polarity of these short basic pulses does not affect the performance of UWB radio system.

  13. Radio/Antenna Mounting System for Wireless Networking under Row-Crop Agriculture Conditions

    Directory of Open Access Journals (Sweden)

    Daniel K. Fisher

    2015-07-01

    Full Text Available Interest in and deployment of wireless monitoring systems is increasing in many diverse environments, including row-crop agricultural fields. While many studies have been undertaken to evaluate various aspects of wireless monitoring and networking, such as electronic hardware components, data-collection procedures, power management, and communication protocols, little information related to physical deployment issues has been reported. To achieve acceptable wireless transmission capability, the radio/antenna must be positioned properly relative to the ground surface or crop canopy to minimize degradation of the radio signal, usually requiring the mounting of the radio/antenna above the canopy. This results in the presence of obstacles to normal agricultural equipment traffic and production operations and potential damage to the wireless monitoring system. A simple and rugged radio/antenna mounting system was designed which could be subjected to encounters with agricultural equipment without suffering physical damage. The mounting system was deployed and tested, and operated successfully following repeated encounters with various agricultural machines and implements. The radio/antenna mount is simple and inexpensive to fabricate using locally available components.

  14. Voice Quality Estimation in Combined Radio-VoIP Networks for Dispatching Systems

    Directory of Open Access Journals (Sweden)

    Jiri Vodrazka

    2016-01-01

    Full Text Available The voice quality modelling assessment and planning field is deeply and widely theoretically and practically mastered for common voice communication systems, especially for the public fixed and mobile telephone networks including Next Generation Networks (NGN - internet protocol based networks. This article seeks to contribute voice quality modelling assessment and planning for dispatching communication systems based on Internet Protocol (IP and private radio networks. The network plan, correction in E-model calculation and default values for the model are presented and discussed.

  15. On the Capacity of Underlay Cognitive Radio Systems

    KAUST Repository

    Sboui, Lokman

    2013-05-05

    Due to the scarcity of frequency spectrum in view of the evolution of wireless communication technologies, the cognitive radio (CR) concept has been introduced to efficiently exploit the available spectrum. This concept consists in introducing unlicensed/secondary users (SU’s) in existing networks to share the spectrum of licensed/primary users (PU’s) without harming primary communications hence the name of “spectrum sharing” technique. We study in this dissertation, the capacity and the achievable rate of the secondary user within various communication settings. We, firstly, investigate the capacity of the (SU’s) at low power regime for Nakagami fading channels and present closed form of the capacity under various types of interference and/or power constraints. We explicitly characterize two regimes where either the interference constraint or the power constraint dictates the optimal power profile. Our framework also highlights the effects of different fading parameters on the secondary link ergodic capacity. Interestingly, we show that the low power regime analysis provides a specific insight on the capacity behavior of CR that has not been reported by previous studies. Next, we determine the spectral efficiency gain of an uplink CR Multi-Input Multi- Output (MIMO) system in which the SU is allowed to share the spectrum with the PU using a specific precoding scheme to communicate with a common receiver. Applied to Rayleigh fading channels, we show, through numerical results, that our proposed scheme enhances considerably the cognitive achievable rate. For instance, in case of a perfect detection of the PU signal, after applying Successive Interference Cancellation (SIC), the CR rate remains non-zero for high Signal to Noise Ratio (SNR) which is usually impossible when we only use space alignment technique. In addition, we show that the rate gain is proportional to the allowed interference threshold by providing a fixed rate even in the high SNR range

  16. Communicating astronomy in a small island state: The unique role of the Mauritius Radio Telescope

    Science.gov (United States)

    Saddul-Hauzaree, S.

    2008-06-01

    The Mauritius Radio Telescope (MRT) is a 2 km x 1 km T-shaped aperture synthesis array that can generate radio images of the southern sky at 151.6 MHz. The sky surveyed can be in the declination range of -70o to -10o. It is located at Bras d'Eau, northeast of Mauritius at latitude 20oS and longitude 60oE. The MRT is a joint project of the University of Mauritius, the Indian Institute of Astrophysics and the Raman Research Institute. One of the main objectives of the MRT is to generate public interest in astronomy. Thus, it is involved in a wide range of onsite outreach activities for young school children. More mature students visiting the telescope learn about sky observation with a radio telescope, get to explore some sets of data, interact with the scientific personnel, get the opportunity to have hands-on experience with image manipulation and can ask a lot of questions on astronomy. This poster gives an overview of the Mauritius Radio Telescope and the attempts of MRT ito communicate astronomy to students as a process and not just as a vast expanse of knowledge. The challenges and dilemmas faced by MRT in conveying astronomy to the general public in a small island state are investigated and presented.

  17. 49 CFR 193.2519 - Communication systems.

    Science.gov (United States)

    2010-10-01

    ... primary communication system that provides for verbal communications between all operating personnel at...) storage capacity must have an emergency communication system that provides for verbal communications... 49 Transportation 3 2010-10-01 2010-10-01 false Communication systems. 193.2519 Section 193.2519...

  18. Radio Astrometry of the Triple Systems Algol and UX Arietis

    Science.gov (United States)

    Peterson, W. M.; Mutel, R. L.; Lestrade, J.-F.; Güdel, M.; Goss, W. M.

    2011-08-01

    We have used multi-epoch long-baseline radio interferometry to determine the proper motion and orbital elements of Algol and UX Arietis, two radio-bright, close binary stellar systems with distant tertiary components. For Algol, we refine the proper motion and outer orbit solutions, confirming the recent result of Zavala et al. that the inner orbit is retrograde. The radio centroid closely tracks the motion of the KIV secondary. In addition, the radio morphology varies from double-lobed at low flux level to crescent-shaped during active periods. These results are most easily interpreted as synchrotron emission from a large, co-rotating meridional loop centered on the K star. If this is correct, it provides a radio-optical frame tie candidate with an uncertainty ±0.5 mas. For UX Arietis, we find an outer orbit solution that accounts for previous very long baseline interferometry observations of an acceleration term in the proper motion fit. The outer orbit solution is also consistent with previously published radial velocity curves and speckle observations of a third body. The derived tertiary mass, 0.75 solar masses, is consistent with the K1 main-sequence star detected spectroscopically. The inner orbit solution favors radio emission from the active K0IV primary only. The radio morphology, consisting of a single, partially resolved emission region, may be associated with the persistent polar spot observed using Doppler imaging.

  19. Communicating embedded systems networks applications

    CERN Document Server

    Krief, Francine

    2013-01-01

    Embedded systems become more and more complex and require having some knowledge in various disciplines such as electronics, data processing, telecommunications and networks. Without detailing all the aspects related to the design of embedded systems, this book, which was written by specialists in electronics, data processing and telecommunications and networks, gives an interesting point of view of communication techniques and problems in embedded systems. This choice is easily justified by the fact that embedded systems are today massively communicating and that telecommunications and network

  20. Advanced satellite communication system

    Science.gov (United States)

    Staples, Edward J.; Lie, Sen

    1992-01-01

    The objective of this research program was to develop an innovative advanced satellite receiver/demodulator utilizing surface acoustic wave (SAW) chirp transform processor and coherent BPSK demodulation. The algorithm of this SAW chirp Fourier transformer is of the Convolve - Multiply - Convolve (CMC) type, utilizing off-the-shelf reflective array compressor (RAC) chirp filters. This satellite receiver, if fully developed, was intended to be used as an on-board multichannel communications repeater. The Advanced Communications Receiver consists of four units: (1) CMC processor, (2) single sideband modulator, (3) demodulator, and (4) chirp waveform generator and individual channel processors. The input signal is composed of multiple user transmission frequencies operating independently from remotely located ground terminals. This signal is Fourier transformed by the CMC Processor into a unique time slot for each user frequency. The CMC processor is driven by a waveform generator through a single sideband (SSB) modulator. The output of the coherent demodulator is composed of positive and negative pulses, which are the envelopes of the chirp transform processor output. These pulses correspond to the data symbols. Following the demodulator, a logic circuit reconstructs the pulses into data, which are subsequently differentially decoded to form the transmitted data. The coherent demodulation and detection of BPSK signals derived from a CMC chirp transform processor were experimentally demonstrated and bit error rate (BER) testing was performed. To assess the feasibility of such advanced receiver, the results were compared with the theoretical analysis and plotted for an average BER as a function of signal-to-noise ratio. Another goal of this SBIR program was the development of a commercial product. The commercial product developed was an arbitrary waveform generator. The successful sales have begun with the delivery of the first arbitrary waveform generator.

  1. Compressive Sensing in Communication Systems

    DEFF Research Database (Denmark)

    Fyhn, Karsten

    2013-01-01

    Wireless communication is omnipresent today, but this development has led to frequency spectrum becoming a limited resource. Furthermore, wireless devices become more and more energy-limited, due to the demand for continual wireless communication of higher and higher amounts of information....... The need for cheaper, smarter and more energy efficient wireless devices is greater now than ever. This thesis addresses this problem and concerns the application of the recently developed sampling theory of compressive sensing in communication systems. Compressive sensing is the merging of signal...... acquisition and compression. It allows for sampling a signal with a rate below the bound dictated by the celebrated Shannon-Nyquist sampling theorem. In some communication systems this necessary minimum sample rate, dictated by the Shannon-Nyquist sampling theorem, is so high it is at the limit of what...

  2. EMI protection for communication systems

    CERN Document Server

    Malaric, Kresimir

    2009-01-01

    This practical reference provides a thorough understanding of how to protect communication systems from intentional and unintentional electromagnetic interference. You learn how to overcome critical problems in both digital and analog communications. This unique resource shows you how to shield equipment from electrical and magnetic fields, design TEM and GTEM-Cell, build capacitive coupling clamps for susceptibility tests, protect electronic equipment with filters, and calculate the measurement uncertainty. You find numerous, well-illustrated examples that make challenging electromagnetics is

  3. Android在数字集群通信终端中的应用%Application of Android in digital trunked radio communication terminal

    Institute of Scientific and Technical Information of China (English)

    谢拥军; 鄢楚平; 汪涵

    2012-01-01

    为了使数字集群通信终端智能化并兼容Android平台丰富的应用,对如何将目前流行的智能操作系统Android应用到数字集群通信终端中进行了研究和实现.对于数字集群通信终端的重要组成部分——电话系统,详细地分析了Android自带的Telephony框架,然后根据TETRA数字集群系统的特点对Telephony框架进行了修改,最后对已修改的Android系统在TI的OMAP3530平台上进行了验证,实现了数字集群通信终端特有的功能.%To intelligentize the digital trunked radio communication terminal and make it compatible with the abundant applications of Android platform, the problemon how to apply the current popular smartphone's Android operating system is researched and implemented to digital trunked radio communication terminal. For the important part of digital trunked radio communication terminal, the telephony framework is analyzed in detail. Then, the telephony system is modified according to the characteristics of the TETRA digital trunked system. At last, the modified Android system is verified on the OMAP3530 platform of texas instruments, and achieved the specific features of the digital trunked communication terminal.

  4. PKS 0347+05: a radio-loud/radio-quiet double active galactic nucleus system triggered in a major galaxy merger

    NARCIS (Netherlands)

    Tadhunter, C. N.; Ramos Almeida, C.; Morganti, R.; Holt, J.; Rose, M.; Dicken, D.; Inskip, K.

    2012-01-01

    We present optical, infrared (IR) and radio observations of the powerful Fanaroff-Riley type II (FR II) radio source PKS 0347+05 (z = 0.3390), and demonstrate that it is a rare example of a radio-loud/radio-quiet double active galactic nucleus (AGN) system, comprising a weak-line radio galaxy (WLRG)

  5. PKS 0347+05: a radio-loud/radio-quiet double active galactic nucleus system triggered in a major galaxy merger

    NARCIS (Netherlands)

    Tadhunter, C. N.; Ramos Almeida, C.; Morganti, R.; Holt, J.; Rose, M.; Dicken, D.; Inskip, K.

    2012-01-01

    We present optical, infrared (IR) and radio observations of the powerful Fanaroff-Riley type II (FR II) radio source PKS 0347+05 (z = 0.3390), and demonstrate that it is a rare example of a radio-loud/radio-quiet double active galactic nucleus (AGN) system, comprising a weak-line radio galaxy (WLRG)

  6. Updates to the NASA Space Telecommunications Radio System (STRS) Architecture

    Science.gov (United States)

    Kacpura, Thomas J.; Handler, Louis M.; Briones, Janette; Hall, Charles S.

    2008-01-01

    This paper describes an update of the Space Telecommunications Radio System (STRS) open architecture for NASA space based radios. The STRS architecture has been defined as a framework for the design, development, operation and upgrade of space based software defined radios, where processing resources are constrained. The architecture has been updated based upon reviews by NASA missions, radio providers, and component vendors. The STRS Standard prescribes the architectural relationship between the software elements used in software execution and defines the Application Programmer Interface (API) between the operating environment and the waveform application. Modeling tools have been adopted to present the architecture. The paper will present a description of the updated API, configuration files, and constraints. Minimum compliance is discussed for early implementations. The paper then closes with a summary of the changes made and discussion of the relevant alignment with the Object Management Group (OMG) SWRadio specification, and enhancements to the specialized signal processing abstraction.

  7. Mobile Communication Systems and Security

    CERN Document Server

    Rhee, Man Young

    2009-01-01

    Mobile Communication Systems and Security arms readers with a thorough understanding of all major cellular air-interface technologies and their security layer techniques. Rhee covers the technological development of wireless mobile communications in compliance with each iterative generation up to 3G systems and beyond, with an emphasis on wireless security aspects. By progressing in a systematic manner, presenting the theory and practice of wireless mobile technologies along with various security problems, readers will gain an intimate sense of how mobile systems operate and how to address com

  8. Fiber-optic communication systems

    CERN Document Server

    Agrawal, Govind P

    2010-01-01

    This book provides a comprehensive account of fiber-optic communication systems. The 3rd edition of this book is used worldwide as a textbook in many universities. This 4th edition incorporates recent advances that have occurred, in particular two new chapters. One deals with the advanced modulation formats (such as DPSK, QPSK, and QAM) that are increasingly being used for improving spectral efficiency of WDM lightwave systems. The second chapter focuses on new techniques such as all-optical regeneration that are under development and likely to be used in future communication systems. All othe

  9. Location-Based Resource Allocation for OFDMA Cognitive Radio Systems

    KAUST Repository

    Ghorbel, Mahdi

    2011-05-01

    Cognitive radio is one of the hot topics for emerging and future wireless communication. It has been proposed as a suitable solution for the spectrum scarcity caused by the increase in frequency demand. The concept is based on allowing unlicensed users, called cognitive or secondary users, to share the unoccupied frequency bands with their owners, called the primary users, under constraints on the interference they cause to them. In order to estimate this interference, the cognitive system usually uses the channel state information to the primary user, which is often impractical to obtain. However, we propose to use location information, which is easier to obtain, to estimate this interference. The purpose of this work is to propose a subchannel and power allocation method which maximizes the secondary users\\' total capacity under the constraints of limited budget power and total interference to the primary under certain threshold. We model the problem as a constrained optimization problem for both downlink and uplink cases. Then, we propose low-complexity resource allocation schemes based on the waterfilling algorithm. The simulation results show the efficiency of the proposed method with comparison to the exhaustive search algorithm.

  10. A Model of Internal Communication in Adaptive Communication Systems.

    Science.gov (United States)

    Williams, M. Lee

    A study identified and categorized different types of internal communication systems and developed an applied model of internal communication in adaptive organizational systems. Twenty-one large organizations were selected for their varied missions and diverse approaches to managing internal communication. Individual face-to-face or telephone…

  11. Reconfigurable mobile radio systems a snapshot of key aspects related to reconfigurability in wireless systems

    CERN Document Server

    Vivier, Guillaume

    2010-01-01

    Different aspects of the reconfigurability of mobile radio systems are analyzed in this book. These include services, object modeling applied to software radio, flexible spectrum management, trade-offs for building a reconfigurable terminal, an example of a pure software radio modem, adaptive MIMO techniques and analog-to-digital converters.

  12. A Novel Keyless Entry System Using Visible Light Communication

    Directory of Open Access Journals (Sweden)

    Kuniyoshi Okuda

    2014-10-01

    Full Text Available A major conventional car key is the mechanical key. When users inserted the key into a cylinder mechanical key and turn, users can unlock. The mechanical key may be able to be worn away for physical contact. And it may be impossible to use. Further the mechanical key may be damaged or destroyed by mischief. So a keyless entry system has been developed. The keyless entry system locks and unlocks using the infrared ray and radio waves communication. The keyless entry system does not require physical contacts. Therefore, the possibilities of damage due to mischief and be worn away are fell. However, the transmission ranges of infrared ray and radio waves communication are not clear. Submitting data might be tapped to the malicious people. If the information is tapped, then you have theft of the car and the risk of car break. We propose a keyless entry system using visible light communication in order to solve this problem. Visible light communication transmits signal using blinking light. Thus the transmission range is clear. The user can transmit the information only to the aimed place. Therefore, the usability is improved. We measure the durations of "take out the remote control", "put the aim" and "takes to unlock key" in order to evaluate the usability in the experiment. We also compared with the infrared ray communication and examined the superiority. Usability is improved in the experimental results, and usability is better than conventional keyless entry system.

  13. Wearable ECG Based on Impulse-Radio-Type Human Body Communication.

    Science.gov (United States)

    Wang, Jianqing; Fujiwara, Takuya; Kato, Taku; Anzai, Daisuke

    2016-09-01

    Human body communication (HBC) provides a promising physical layer for wireless body area networks (BANs) in healthcare and medical applications, because of its low propagation loss and high security characteristics. In this study, we have developed a wearable electrocardiogram (ECG) which employs impulse radio (IR)-type HBC technology for transmitting vital signals on the human body in a wearable BAN scenario. The HBC-based wearable ECG has two excellent features. First, the wideband performance of the IR scheme contributed to very low radiation power so that the transceiver is easy to satisfy the extremely weak radio laws, which does not need a license. This feature can provide big convenience in the use and spread of the wearable ECG. Second, the realization of common use of sensing and transmitting electrodes based on time sharing and capacitive coupling largely simplified the HBC-based ECG structure and contributed to its miniaturization. To verify the validity of the HBC-based ECG, we evaluated its communication performance and ECG acquisition performance. The measured bit error rate, smaller than 10 (-3) at 1.25 Mb/s, showed a good physical layer communication performance, and the acquired ECG waveform and various heart-rate variability parameters in time and frequency domains exhibited good agreement with a commercially available radio-frequency ECG and a Holter ECG. These results sufficiently showed the validity and feasibility of the HBC-based ECG for healthcare applications. This should be the first time to have realized a real-time ECG transmission by using the HBC technology.

  14. Throughput Analysis for Cognitive Radio (CR Systems

    Directory of Open Access Journals (Sweden)

    Ahmed S.Kadhim

    2012-08-01

    Full Text Available In cognitive radio networks, the secondary network (users are allowed to utilize the frequency bands of primary network (users when they are not currently being used. To support this function, the secondary users are required to sense the radio frequency environment, and once the primary user is found to be active, the secondary users have to vacate the channel within certain amount of time. There are two parameters related to channel sensing: probability of detection and probability of false alarm. The higher the detection probability, the better the primary users can be protected. However, from the secondary users’ perspective, the lower the false alarm probability, the more chances the channel can be reused,thus the higher the achievable throughput for the secondary users. In this paper, we study the fundamental tradeoff between sensing capability and achievable throughput of the secondary users. Also, we present a design for sensing slot duration to maximize the achievable throughput for the secondary users under the constraint that the primary users are sufficiently protected. Using energy detection scheme, an optimal sensing time which provides the best tradeoff is given. Cooperative sensing is alsostudied based on the methodology of the proposed sensing throughput tradeoff. Computer simulations arepresented to evaluate the proposed tradeoff methodology

  15. OFDM systems for wireless communications

    CERN Document Server

    Narasimhamurthy, Adarsh

    2010-01-01

    Orthogonal Frequency Division Multiplexing (OFDM) systems are widely used in the standards for digital audio/video broadcasting, WiFi and WiMax. Being a frequency-domain approach to communications, OFDM has important advantages in dealing with the frequency-selective nature of high data rate wireless communication channels. As the needs for operating with higher data rates become more pressing, OFDM systems have emerged as an effective physical-layer solution.This short monograph is intended as a tutorial which highlights the deleterious aspects of the wireless channel and presents why OFDM is

  16. Time reversal communication system

    Science.gov (United States)

    Candy, James V.; Meyer, Alan W.

    2008-12-02

    A system of transmitting a signal through a channel medium comprises digitizing the signal, time-reversing the digitized signal, and transmitting the signal through the channel medium. The channel medium may be air, earth, water, tissue, metal, and/or non-metal.

  17. A MATLAB Library for Rapid Prototyping of Wireless Communications Algorithms with the Universal Software Radio Peripheral (USRP) Radio Family

    Science.gov (United States)

    2013-06-01

    Peripheral (USRP) family of radio hardware using MATLAB. This library enables fast prototyping of algorithms on SDRs. 15. SUBJECT TERMS USRP, MATLAB, GNU ...code) (301) 394-3102 Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18 Contents 1. Introduction 1 1.1 Challenges of GNU Radio ...multiply conjugate cc block (conjugate multiply) in GNU Radio . Arrows denote inheritance from the target block. Note the complexity of the hierarchy

  18. Location-based resource allocation for OFDMA cognitive radio systems

    KAUST Repository

    Nam, Haewoon

    2010-01-01

    In cognitive radio systems, in order for the secondary users to opportunistically share the spectrum without interfering the primary users, an accurate spectrum measurement and a precise estimation of the interference at the primary users are necessary but are challenging tasks. Since it is impractical in cognitive radio systems to assume that the channel state information of the interference link is available at the cognitive transmitter, the interference at the primary users is hard to be estimated accurately. This paper introduces a resource allocation algorithm for OFDMA-based cognitive radio systems, which utilizes location information of the primary and secondary users instead of the channel state information of the interference link. Simulation results show that it is indeed effective to incorporate location information into resource allocation so that a near-optimal capacity is achieved.

  19. Atmospheric Optical Communication Systems.

    Science.gov (United States)

    1981-02-01

    Tnteral system noise due to dark current id is Oven by . 1d = 2qGrB"" (2-9) Dark current is due to detecor biasing in some instances, and in somue...8217 without extansive pro- gr-=:ing exer’ence. Although. the znodel is designed to be Lteracdve, slight mod-.- i~cadons winl ezw :&31 r~ing of the progrsm

  20. The control system of the 3 mm band SIS receiver for the Sardinia Radio Telescope

    Science.gov (United States)

    Ladu, A.; Ortu, P.; Saba, A.; Pili, M.; Guadiomonte, F.; Navarrini, A.; Urru, E.; Pisanu, T.; Valente, G.; Marongiu, P.; Mazzarella, G.

    2016-07-01

    We present the control system of the 84-116 GHz (3 mm band) Superconductor-Insulator-Superconductor (SIS) heterodyne receiver to be installed at the Gregorian focus of the Sardinia Radio Telescope (SRT). The control system is based on a single-board computer from Raspberry, on microcontrollers from Arduino, and on a Python program for communication between the receiver and the SRT antenna control software, which remotely controls the backshorttuned SIS mixer, the receiver calibration system and the Local Oscillator (LO) system.

  1. Impact of the integrated Radio Communication Project in Nepal, 1994-1997.

    Science.gov (United States)

    Storey, D; Boulay, M; Karki, Y; Heckert, K; Karmacharya, D M

    1999-01-01

    The Radio Communication Project (RCP) in Nepal is an ongoing, theory-based, multimedia reproductive health campaign which began in 1995. It consists of two entertainment-education radio serials (a soap opera for the general public and a dramatized distance education serial for health workers), additional radio spot advertisements and promotions, and complementary print materials. This paper examines impact data from a variety of sources, including a pre- and postpanel survey of currently married women (N = 1905), three waves of clinic-based observations of client-provider interactions (N = 240 per wave) and client exit interviews (N = 240 per wave), and 2 years of clinic service statistics, in order to draw inferences about the separate and combined effects of the RCP components. The study found increased health worker interpersonal interaction skills, improved quality of client-provider interactions, increased client self-efficacy in dealing with health workers, improved client attitudes toward health services and toward the practice of family planning, increased adoption of family planning, and increased family planning service utilization, all attributable to the RCP. The panel data allowed statistical control of the influence of predisposing factors before the campaign on postcampaign ideation and behavior. The effect of the RCP on contraceptive behavior was largely indirect through its influence on ideation. Implications for the design of integrated, multimedia, entertainment-education campaigns and integrated evaluation designs are discussed.

  2. A Lightweight Radio Propagation Model for Vehicular Communication in Road Tunnels.

    Science.gov (United States)

    Qureshi, Muhammad Ahsan; Noor, Rafidah Md; Shamim, Azra; Shamshirband, Shahaboddin; Raymond Choo, Kim-Kwang

    2016-01-01

    Radio propagation models (RPMs) are generally employed in Vehicular Ad Hoc Networks (VANETs) to predict path loss in multiple operating environments (e.g. modern road infrastructure such as flyovers, underpasses and road tunnels). For example, different RPMs have been developed to predict propagation behaviour in road tunnels. However, most existing RPMs for road tunnels are computationally complex and are based on field measurements in frequency band not suitable for VANET deployment. Furthermore, in tunnel applications, consequences of moving radio obstacles, such as large buses and delivery trucks, are generally not considered in existing RPMs. This paper proposes a computationally inexpensive RPM with minimal set of parameters to predict path loss in an acceptable range for road tunnels. The proposed RPM utilizes geometric properties of the tunnel, such as height and width along with the distance between sender and receiver, to predict the path loss. The proposed RPM also considers the additional attenuation caused by the moving radio obstacles in road tunnels, while requiring a negligible overhead in terms of computational complexity. To demonstrate the utility of our proposed RPM, we conduct a comparative summary and evaluate its performance. Specifically, an extensive data gathering campaign is carried out in order to evaluate the proposed RPM. The field measurements use the 5 GHz frequency band, which is suitable for vehicular communication. The results demonstrate that a close match exists between the predicted values and measured values of path loss. In particular, an average accuracy of 94% is found with R2 = 0.86.

  3. Cognitive Wireless Communications - A paradigm shift in dealing with radio resources as a prerequisite for the wireless network of the future - An overview on the topic of cognitive wireless technologies

    Science.gov (United States)

    Haustein, Thomas; Stanczak, Slawomir; Wolisz, Adam; Jondral, Friedrich; Schotten, Hans; Kraemer, Rolf; Mück, Markus; Mennenga, Horst; Bender, Paul

    2016-07-01

    Wireless radio communications systems form the basis for mobile network connections in the digital society. A limited amount of radio spectrum and a spatially densified use of wireless communications systems require a resource-efficient use of the spectrum. Mechanisms of cognitive radio may hold the key to a more efficient use of the available spectrum under consideration of quality of service requirements. These mechanisms take advantage of location-specific knowledge of the wireless channel occupation in the dimensions of frequency, time, location and direction in space and therefore enable co-existent and reliable wireless communication. The authors give an introduction to the status of cognitive wireless communication technology, which represents the starting point of a series of research projects promoted by BMBF during 2012-2014.

  4. Chaotic systems in optical communications

    Science.gov (United States)

    Siuzdak, J.

    2016-09-01

    Communications application of chaotic oscillations of lasers with optoelectronic feedback was discussed. The possibility of eavesdropping of the transmission was analyzed. It was proved that if the rogue party precisely knows parameters of the chaotic system it may recreate the entire signals solely by observation of the optical signal power causing security breach.

  5. Communication-based positioning systems: past, present and prospects

    Institute of Scientific and Technical Information of China (English)

    Guan-Yi Ma; Qing-Tao Wan; Tong Gan

    2012-01-01

    This paper reviews positioning systems in the context of communication systems.First,the basic positioning technique is described for location based service (LBS) in mobile communication systems.Then the high integrity global positioning system (iGPS) is introduced in terms of aspects of what it is and how the low Earth orbit (LEO) Iridium telecommunication satellites enhance the global positioning system (GPS).Emphasis is on the Chinese Area Positioning System (CAPS) which is mainly based on commercial geostationary (GEO) communication satellites,including decommissioned GEO and inclined geosynchronous communication satellites.Characterized by its low cost,high flexibility,wide-area coverage and ample frequency resources,a distinctive feature of CAPS is that its navigation messages are generated on the ground,then uploaded to and forwarded by the communication satellites.Fundamental principles and key technologies applied in the construction of CAPS are presented in detail from the CAPS validation phase to its experimental system setup.A prospective view of CAPS has concluded it to be a seamless,high accuracy,large capacity navigation and communication system which can be achieved by expanding it world wide and enhancing it with LEO satellites and mobile base stations.Hence,this system is a potential candidate for the next generation of radio navigation after GPS.

  6. Communication-based positioning systems: past, present and prospects

    Science.gov (United States)

    Ma, Guan-Yi; Wan, Qing-Tao; Gan, Tong

    2012-06-01

    This paper reviews positioning systems in the context of communication systems. First, the basic positioning technique is described for location based service (LBS) in mobile communication systems. Then the high integrity global positioning system (iGPS) is introduced in terms of aspects of what it is and how the low Earth orbit (LEO) Iridium telecommunication satellites enhance the global positioning system (GPS). Emphasis is on the Chinese Area Positioning System (CAPS) which is mainly based on commercial geostationary (GEO) communication satellites, including decommissioned GEO and inclined geosynchronous communication satellites. Characterized by its low cost, high flexibility, wide-area coverage and ample frequency resources, a distinctive feature of CAPS is that its navigation messages are generated on the ground, then uploaded to and forwarded by the communication satellites. Fundamental principles and key technologies applied in the construction of CAPS are presented in detail from the CAPS validation phase to its experimental system setup. A prospective view of CAPS has concluded it to be a seamless, high accuracy, large capacity navigation and communication system which can be achieved by expanding it world wide and enhancing it with LEO satellites and mobile base stations. Hence, this system is a potential candidate for the next generation of radio navigation after GPS.

  7. 5G Wireless Communication Systems

    Directory of Open Access Journals (Sweden)

    Saddam Hossain

    2013-10-01

    Full Text Available As a subscriber becomes more aware of the mobile phone technology, he/she will seek for anappropriate package all together, including all the advanced features of a cellular phone can have. Hence, the search for new technology is always the main intention of the prime cell phone giants to out innovate their competitors. In addition, the main purpose of the fifth generation wireless networks (5G Wireless networks is planned to design the best wireless world that is free from limitations and hindrance of the previous generations.5G technologies will change the way most high bandwidth users access their Mobile Radio Communication (MRC. So, this paper represents, great evolution of 1G (First Generation to 4G yield 5G, introduction to 5G technologies, why there is a need for 5G, advantages of 5G networks technology, exceptional applications, Quality of Service (QoS, 5G network architecture-The MasterCore as well as hardware and software for the 5GMasterCore technology

  8. Global services systems - Space communication

    Science.gov (United States)

    Shepphird, F. H.; Wolbers, H. L.

    1979-01-01

    The requirements projected to the year 2000 for space-based global service systems, including both personal communications and innovative services, are developed based on historic trends and anticipated worldwide demographic and economic growth patterns. The growing demands appear to be best satisfied by developing larger, more sophisticated space systems in order to reduce the size, complexity, and expense of ground terminals. The availability of low-cost ground terminals will, in turn, further stimulate the generation of new services and new customers.

  9. Radios in the Classroom: Curriculum Integration and Communication Skills. ERIC Digest.

    Science.gov (United States)

    Ninno, Anton

    Teachers have explored the use of radio in the classroom almost since radio technology entered into the mainstream of society, yet radio remains a relatively unused mode of instruction. This Digest describes several radio applications and summarizes various radio activities to assist teachers in integrating technology into the curriculum.…

  10. Space Telecommunications Radio System Software Architecture Concepts and Analysis

    Science.gov (United States)

    Handler, Louis M.; Hall, Charles S.; Briones, Janette C.; Blaser, Tammy M.

    2008-01-01

    The Space Telecommunications Radio System (STRS) project investigated various Software Defined Radio (SDR) architectures for Space. An STRS architecture has been selected that separates the STRS operating environment from its various waveforms and also abstracts any specialized hardware to limit its effect on the operating environment. The design supports software evolution where new functionality is incorporated into the radio. Radio hardware functionality has been moving from hardware based ASICs into firmware and software based processors such as FPGAs, DSPs and General Purpose Processors (GPPs). Use cases capture the requirements of a system by describing how the system should interact with the users or other systems (the actors) to achieve a specific goal. The Unified Modeling Language (UML) is used to illustrate the Use Cases in a variety of ways. The Top Level Use Case diagram shows groupings of the use cases and how the actors are involved. The state diagrams depict the various states that a system or object may be in and the transitions between those states. The sequence diagrams show the main flow of activity as described in the use cases.

  11. Antenna system characteristic and solar radio burst observation

    CERN Document Server

    Li, Sha; Chen, Zhijun; Wang, Wei; Liu, Donghao

    2015-01-01

    Chinese Spectral Radio Heliograph (CSRH) is an advanced aperture synthesis solar radio heliograph, developed by National Astronomical Observatories, Chinese Academy of Sciences independently. It consists of 100 reflector antennas, which are grouped into two antenna arrays (CSRH-I and CSRH-II) for low and high frequency bands respectively. The frequency band of CSRH-I is 0.4-2GHz and for CSRH-II, the frequency band is 2-15GHz. In the antenna and feed system, CSRH uses an Eleven feed to receive signals coming from the Sun, the radiation pattern with lower side lobe and back lobe of the feed is well radiated. The characteristics of gain G and antenna noise temperature T effect the quality of solar radio imaging. For CSRH, measured G is larger than 60 dBi and $ T $ is less than 120K, after CSRH-I was established, we have successfully captured a solar radio burst between 1.2-1.6GHz on November 12, 2010 through this instrument and this event was confirmed through the observation of Solar Broadband Radio Spectromete...

  12. Understanding the evolution of close binary systems with radio pulsars

    CERN Document Server

    Benvenuto, O G; Horvath, J E

    2014-01-01

    We calculate the evolution of close binary systems (CBSs) formed by a neutron star (behaving as a radio pulsar) and a normal donor star, evolving either to helium white dwarf (HeWD) or ultra short orbital period systems. We consider X-ray irradiation feedback and evaporation due to radio pulsar irradiation. We show that irradiation feedback leads to cyclic mass transfer episodes, allowing CBSs to be observed in-between as binary radio pulsars under conditions in which standard, non-irradiated models predict the occurrence of a low mass X-ray binary. This behavior accounts for the existence of a family of eclipsing binary systems known as redbacks. We predict that redback companions should almost fill their Roche lobe, as observed in PSR J1723-2837. This state is also possible for systems evolving with larger orbital periods. Therefore, binary radio pulsars with companion star masses usually interpreted as larger than expected to produce HeWDs may also result in such {\\it quasi - Roche Lobe Overflow} states, r...

  13. Antenna Technology and other Radio Frequency (RF) Communications Activities at the Glenn Research Center in Support of NASA's Exploration Vision

    Science.gov (United States)

    Miranda, Felix A.

    2007-01-01

    NASA s Vision for Space Exploration outlines a very ambitious program for the next several decades of the Space Agency endeavors. Ahead is the completion of the International Space Station (ISS); safely flight the shuttle (STS) until 2010; develop and fly the Crew Exploration Vehicle (Orion) by no later than 2014; return to the moon by no later than 2020; extend human presence across the solar system and beyond; implement a sustainable and affordable human and robotic program; develop supporting innovative technologies, knowledge and infrastructure; and promote international and commercial participation in exploration. To achieve these goals, a series of enabling technologies must be developed or matured in a timely manner. Some of these technologies are: spacecraft RF technology (e.g., high power sources and large antennas which using surface receive arrays can get up to 1 Gbps from Mars), uplink arraying (reduce reliance on large ground-based antennas and high operation costs; single point of failure; enable greater data-rates or greater effective distance; scalable, evolvable, flexible scheduling), software define radio (i.e., reconfigurable, flexible interoperability allows for in flight updates open architecture; reduces mass, power, volume), and optical communications (high capacity communications with low mass/power required; significantly increases data rates for deep space). This presentation will discuss some of the work being performed at the NASA Glenn Research Center, Cleveland, Ohio, in antenna technology as well as other on-going RF communications efforts.

  14. Generalized location-based resource allocation for OFDMA cognitive radio systems

    KAUST Repository

    Ben Ghorbel, Mahdi

    2010-09-01

    Cognitive radio is one of the hot topics for emerging and future wireless communication. Cognitive users can share channels with primary users under the condition of non interference. In order to compute this interference, the cognitive system usually use the channel state information of the primary user which is often impractical to obtain. However, using location information, we can estimate this interference by pathloss computation. In this paper, we introduce a low-complexity resource allocation algorithm for orthogonal frequency division multiple access (OFDMA) based cognitive radio systems, which uses relative location information between primary and secondary users to estimate the interference. This algorithm considers interference with multiple primary users having different thresholds. The simulation results show the efficiency of the proposed algorithm by comparing it with an optimal exhaustive search method. © 2010 IEEE.

  15. A Low-Cost Time-Hopping Impulse Radio System for High Data Rate Transmission

    Directory of Open Access Journals (Sweden)

    Jinyun Zhang

    2005-03-01

    Full Text Available We present an efficient, low-cost implementation of time-hopping impulse radio that fulfills the spectral mask mandated by the FCC and is suitable for high-data-rate, short-range communications. Key features are (i all-baseband implementation that obviates the need for passband components, (ii symbol-rate (not chip rate sampling, A/D conversion, and digital signal processing, (iii fast acquisition due to novel search algorithms, and (iv spectral shaping that can be adapted to accommodate different spectrum regulations and interference environments. Computer simulations show that this system can provide 110 Mbps at 7–10 m distance, as well as higher data rates at shorter distances under FCC emissions limits. Due to the spreading concept of time-hopping impulse radio, the system can sustain multiple simultaneous users, and can suppress narrowband interference effectively.

  16. Adaptive Traffic Route Control in QoS Provisioning for Cognitive Radio Technology with Heterogeneous Wireless Systems

    Science.gov (United States)

    Yamamoto, Toshiaki; Ueda, Tetsuro; Obana, Sadao

    As one of the dynamic spectrum access technologies, “cognitive radio technology,” which aims to improve the spectrum efficiency, has been studied. In cognitive radio networks, each node recognizes radio conditions, and according to them, optimizes its wireless communication routes. Cognitive radio systems integrate the heterogeneous wireless systems not only by switching over them but also aggregating and utilizing them simultaneously. The adaptive control of switchover use and concurrent use of various wireless systems will offer a stable and flexible wireless communication. In this paper, we propose the adaptive traffic route control scheme that provides high quality of service (QoS) for cognitive radio technology, and examine the performance of the proposed scheme through the field trials and computer simulations. The results of field trials show that the adaptive route control according to the radio conditions improves the user IP throughput by more than 20% and reduce the one-way delay to less than 1/6 with the concurrent use of IEEE802.16 and IEEE802.11 wireless media. Moreover, the simulation results assuming hundreds of mobile terminals reveal that the number of users receiving the required QoS of voice over IP (VoIP) service and the total network throughput of FTP users increase by more than twice at the same time with the proposed algorithm. The proposed adaptive traffic route control scheme can enhance the performances of the cognitive radio technologies by providing the appropriate communication routes for various applications to satisfy their required QoS.

  17. NSLS-II Radio Frequency Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rose J.; Gao F.; Goel, A.; Holub, B.; Kulpin, J.; Marques, C.; Yeddulla, M.

    2015-05-03

    The National Synchrotron Light Source II is a 3 GeV X-ray user facility commissioned in 2014. The NSLS-II RF system consists of the master oscillator, digital low level RF controllers, linac, booster and storage ring RF sub-systems, as well as a supporting cryogenic system. Here we will report on RF commissioning and early operation experience of the system.

  18. Cognitive radio technology and its application in military communication%认知无线电技术及在军事通信中的应用

    Institute of Scientific and Technical Information of China (English)

    费利军; 王亚鸽

    2014-01-01

    The cognitive radio(CR)is a new concept following the software radio in the communication field,and it focu-ses on the adjusting the system running parameters on the basis of sensing surrounding. The concept of CR and its relation with software radio are described in this paper. Its structure and key technologies are introduced. The advantages of CR in the mili-tary communication and the challenge it is facing are analyzed. It has a positive role in upgrade construction of the communica-tion systems in China.%认知无线电是通信领域在软件无线电概念之后出现的又一新概念,其主要关注于系统通过感知操作环境的变化调整系统工作参数。叙述了认知无线电的概念及与软件无线电的关系,对其构架和关键技术进行了介绍,并分析了认知无线电在军事通信领域的优势及面临的挑战,对于我军通信系统的升级建设具有积极作用。

  19. Short-range communication system

    Science.gov (United States)

    Alhorn, Dean C. (Inventor); Howard, David E. (Inventor); Smith, Dennis A. (Inventor)

    2012-01-01

    A short-range communication system includes an antenna, a transmitter, and a receiver. The antenna is an electrical conductor formed as a planar coil with rings thereof being uniformly spaced. The transmitter is spaced apart from the plane of the coil by a gap. An amplitude-modulated and asynchronous signal indicative of a data stream of known peak amplitude is transmitted into the gap. The receiver detects the coil's resonance and decodes same to recover the data stream.

  20. Energy-Efficient Power Allocation of Cognitive Radio Systems without CSI at the Transmitter

    KAUST Repository

    Sboui, Lokman

    2015-01-07

    Two major issues are facing today’s wireless communications evolution: -Spectrum scarcity: Need for more bandwidth. As a solution, the Cognitive Radio (CR) paradigm, where secondary users (unlicensed) share the spectrum with licensed users, was introduced. -Energy consumption and CO2 emission: The ICT produce 2% of global CO2 emission (equivalent to the aviation industry emission). The cellular networks produces 0.2%. As solution energy efficient systems should be designed rather than traditional spectral efficient systems. In this work, we aim to determine the optimal energy efficient power allocation of CR when the channel state information at the transmitter CSI-T is not available.

  1. Baseband Transceiver Design of a High Definition Radio FM System Using Joint Theoretical Analysis and FPGA Implementation

    Directory of Open Access Journals (Sweden)

    Chien-Sheng Chen

    2014-01-01

    Full Text Available Advances in wireless communications have enabled various technologies for wireless digital communication. In the field of digital radio broadcasting, several specifications have been proposed, such as Eureka-147 and digital radio mondiale (DRM. These systems require a new spectrum assignment, which incurs heavy cost due to the depletion of the available spectrum. Therefore, the in-band on-channel (IBOC system has been developed to work in the same band with the conventional analog radio and to provide digital broadcasting services. This paper discusses the function and algorithm of the high definition (HD radio frequency modulation (FM digital radio broadcasting system. Content includes data format allocation, constellation mapping, orthogonal frequency division multiplexing (OFDM modulation of the transmitter, timing synchronization, OFDM demodulation, integer and fraction carrier frequency (integer carrier frequency offset (ICFO and fractional CFO (FCFO estimation, and channel estimation of the receiver. When we implement this system to the field programmable gate array (FPGA based on a hardware platform, both theoretical and practical aspects have been considered to accommodate the available hardware resources.

  2. Study on Airspace Covert Communication Algorithm of Covert Communication System

    Directory of Open Access Journals (Sweden)

    Yinpu Zhang

    2012-04-01

    Full Text Available Based on the security of information transmission through network in the information society, the paper puts forward covert communication technology which is more reliable than the prior encryption algorithm, analyzes channel covertness and information hiding of covert communication technology based on spread-spectrum communication technology, and establishes a covert communication system including image steganalysis, Arnold transformation and scrambling of carrier image, embedding of secret information, generation of encrypted image and recovering of carrier image by image-based covert communication technology. The simulation result shows: in order to ensure there is no serious degrading problem after embedding the secret information, the carrier image must have a large capacity; the larger the scrambling times is, the better the scrambling and encrypting effect is. Therefore, the airspace covert communication algorithm based on spread-spectrum communication technology well achieves safe transmission of information and has good application prospect.

  3. A paid radio advertising campaign to promote parent-child communication about alcohol.

    Science.gov (United States)

    Surkan, Pamela J; Dejong, William; Herr-Zaya, Kathleen M; Rodriguez-Howard, Mayra; Fay, Kevin

    2003-01-01

    This study assessed the impact of a paid radio commercial designed to promote parent-child communication about alcohol use and sponsored by the Bureau of Substance Abuse Services, Massachusetts Department of Public Health. A random-digit-dial telephone survey of parents or guardians of children ages 10-17 years was conducted after a four-week advertising flight. Respondents with unassisted recall of the commercial more often disagreed that parent-child discussion is useful only if children have begun to experiment with alcohol, and more often reported having three or more parent-child discussions about alcohol compared to those who did not recall the commercial. Findings suggest the potential benefit of paid media campaigns to encourage parents to talk with their children about alcohol.

  4. Concurrent communication and sensing in cognitive radio devices: challenges and an enabling solution

    DEFF Research Database (Denmark)

    Tsakalaki, Elpiniki; Alrabadi, Osama; Tatomirescu, Alexandru

    2014-01-01

    Cognitive Radios (CRs) need to continuously monitor the availability of unoccupied spectrum. Prior work on spectrum sensing mainly focused on time-slotted schemes where sensing and communication take place on different time periods in the same frequency. This however leads to a) limited CR...... throughput as data transmissions need to be interrupted for the sensing task, and b) unreliable detection performance since sensing happens in specific confined time durations. The paper describes the basic design challenges and hardware requirements that restrain CRs from simultaneously and continuously...... sensing the spectrum while transmitting in the same frequency band. The paper then describes a novel approach based on spatial filtering that promises to empower CRs with concurrent transmission and sensing capabilities. The idea is to equip the CR with redundant transmit antennas for forming an adaptive...

  5. Compact mobile-reader system for two-way wireless communication, tracking and status monitoring for transport safety and security

    Science.gov (United States)

    Tsai, Han-Chung; Liu, Yung Y.; Lee, Hok L.; Craig, Brian; Byrne, Kevin; Mittal, Ketan; Scherer, Justin C.

    2016-12-06

    A system for monitoring a plurality radio frequency identification tags is described. The system uses at least one set of radio frequency identification tags. Each tag is attached to a container and includes several sensors for detecting physical conditions of said container. The system includes at least one autonomous intermediate reader in wireless communication with the frequency identification tags. The intermediate reader includes external wireless communication system, intermediate reader logic controller, and a self-contained rechargeable power supply. The system uses a central status reporting system in communication the intermediate reader.

  6. Control of active reflector system for radio telescope

    Science.gov (United States)

    Zhou, Guo-hua; Li, Guo-ping; Zhang, Yong; Zhang, Zhen-chao

    2016-10-01

    According to the control requirements of the active reflector surface in the 110 m radio telescope at QiTai(QTT) Xinjiang, a new displacement actuator and a new displacement control system were designed and manufactured and then their characteristics were tested by a dual-frequency laser interferometer in the micro-displacement laboratory. The displacement actuator was designed by a scheme of high precision worm and roller screw structures, and the displacement control system was based on a ARM micro-processor. Finally, the S curve acceleration control methods were used to design the hardware platform and software algorithm for the active reflection surface of the control system. The test experiments were performed based on the laser metrology system on an active reflector close-loop antenna prototype for large radio telescope. Experimental results indicate that it achieves a 30 mm working stroke and 5 μm RMS motion resolution. The accuracy (standard deviation) is 3.67 mm, and the error between the determined and theoretical values is 0.04% when the rated load is 300 kg, the step is 2 mm and the stroke is 30mm. Furthermore, the active reflector integrated system was tested by the laser sensors with the accuracy of 0.25 μm RMS on 4-panel radio telescope prototype, the measurement results show that the integrated precision of the active reflector closed-loop control system is less than 5 μm RMS, and well satisfies the technical requirements of active reflector control system of the QTT radio telescope in 3 mm wavelength.

  7. Design and Experimental Investigation for Improving the High Frequency Radio Communication Links between Benghazi-Libya and Sfax-Tunisia.

    Directory of Open Access Journals (Sweden)

    Mohamed Yousef Ahmed Abou-Hussein

    2014-02-01

    Full Text Available In this study, we have experimentally planned to replicate the positive results of the application of ionospheric prediction method to design and improve the high frequency (HF radio communication links between Benghazi-Libya and Sfax-Tunisia. The central radio propagation laboratory (CRPL method of ionospheric prediction of the National Bureau of Standards (NBS in U.S.A was used in the calculations of the optimal working frequencies for reliable HF radio communication links between Benghazi-Libya and Sfax-Tunisia. The results were drawn in the form of curves by using the computer. The computer was used to measure the received signal level variation of a frequency 17.500 Megahertz (MHz, which was transmitted with a power of 100 Kilowatt (KW from the Tunis Republic Broadcasting station in SFAX city, directed to the east region. The measurements were taken during daytime's for winter (December, January& February and summer (June, July & August seasons.

  8. PKS0347+05: a radio-loud/radio-quiet double AGN system triggered in a major galaxy merger

    CERN Document Server

    Tadhunter, C; Morganti, R; Holt, J; Rose, M; Dicken, D; Inskip, K

    2012-01-01

    We present optical, infrared and radio observations of the powerful FRII radio source PKS0347+05 (z=0.3390), and demonstrate that it is a rare example of a radio-loud/radio-quiet double AGN system, comprising a weak line radio galaxy (WLRG) separated by 25 kpc (in projection) from a Seyfert 1 nucleus at the same redshift. Our deep Gemini optical images show a highly disturbed morphology, with a warped dust lane crossing through the halo and nuclear regions of the radio galaxy host, tidal tails, and a bridge connecting the radio galaxy to the Seyfert 1 nucleus. Spectral synthesis modelling of our Gemini optical spectrum of the radio galaxy shows evidence for a reddened young stellar population of age <100 Myr. Further evidence for recent star formation activity in this source is provided by the detection of strong PAH features in mid-IR Spitzer/IRS spectra. Together, these observations support a model in which both AGN have been triggered simultaneously in a major galaxy merger. However, despite the presenc...

  9. Expedience of application of MIMO systems of digital communication for complex chaotic signal transmission

    OpenAIRE

    Vasyuta, K. S.; Zakharchenko, I. V.; Ozerov, S. V.

    2015-01-01

    The paper discusses the expediency of using MIMO digital systems for transmission of chaotic signals as a way of partial solution of electromagnetic compatibility of perspective broadband communication systems with an existing class of narrow-band radio-technical systems.

  10. Community Participation, Cultural Discourse, and Health Education Projects in Developing Areas: The Case of the Radio Communication Project in Nepal

    Science.gov (United States)

    Linn, J. Gary

    2008-01-01

    In this article, the author comments on the article by Dutta and Basnyat (see EJ802883) that provides an insightful and comprehensive critique of a United States Agency for International Development (USAID) entertainment-education program, The Radio Communication Program (RCP) in Nepal, which has been reported to be highly participatory. Despite…

  11. Radio Wave Propagation for Communication on and around Mars. Part 1; Highlights: Propagation Through Mars Environment

    Science.gov (United States)

    Ho, Christian; Golshan, Nasser

    1999-01-01

    We recommend to use the dayside Martian ionosphere as a reflector for global communication, because the dayside ionosphere has stable density peak and usable critic frequency. This is very crucial for the future Mars ground to around communication. The dayside ionosphere has been well modeled as a Chapman layer. We suggest to perform the Martian nightside ionospheric modeling study. Because the nightside ionosphere has very little measurements available, we propose to drop a digital ionosond instrument into the Mars surface for data collection. Even though the Martian tropospheric radio refractivity has small value, it still can cause the ray bending and multipath effects. We recommend to perform an accurate calculation on excess phase and group delays (range and time delays). Other effects, such as range rate errors, appearance angle deviation, defocusing loss on Mars, etc. are also needed to be estimated. Ice depolarization effects due to Martian clouds on radio waves is unknown yet, which is expected to be small, because lower optical depth and thinner layer of cloud: Total Martian atmospheric gaseous attenuation is expected to be less than 1 dB on microwaves band, because the Martian atmosphere has very low concentration in uncondensed H2O and O2. An accurate calculation for zenith opacity requires the information about scale heights of H2O and O2 distribution. An accurate water vapor altitude profile at Mars is not available yet. Under the normal condition, CO2 and N2 gases do not have electric or magnetic dipoles and do not absorb electromagnetic energy from the waves. However, they may generate the dipoles through a collision and interact with waves under a high density condition and absorb electromagnetic waves in the infrared and visible band. Dust storm is most dominant factor to the radio wave attenuation. Large Martian dust storm can cause at least 3 dB or higher loss to Ka band wave. For a normal dust storm, the attenuation is about 1 dB. The

  12. Kafedra radiotekhnichnykh prystroiv ta system [Department of radio engineering devices and systems

    Directory of Open Access Journals (Sweden)

    V. P. Taranenko

    1998-09-01

    Full Text Available The department was founded in 1945 after the division of the department receiving and transmitting devices into two: radio receivers and radio transmitters in accordance with the direction and content of research the educational process changed its name to the radio engineering devices and systems. first department was headed by a famous scientist, corresponding member of the Academy of Sciences, Professor Semen Isaakovich Tetelbaum. After his death in 1958 the department was headed by his disciple, Professor Vadim Pavlovich Taranenko. Department is leading the preparation of bachelors and masters in "radio". It provides training in such subjects as radio devices, radio systems, computers, programming, and computer graphics, signal generation devices, computer-aided design in electronics, radio, Radiocomponents and fundamentals of microelectronics, electronic and quantum devices microwave, television basics, devices and systems TV and others. the Department scientific-methodical commission of the Ministry of Education of Ukraine towards the "radio", headed by the dean of the radio department prof. Pravda V.I.

  13. Cyber security with radio frequency interferences mitigation study for satellite systems

    Science.gov (United States)

    Wang, Gang; Wei, Sixiao; Chen, Genshe; Tian, Xin; Shen, Dan; Pham, Khanh; Nguyen, Tien M.; Blasch, Erik

    2016-05-01

    Satellite systems including the Global Navigation Satellite System (GNSS) and the satellite communications (SATCOM) system provide great convenience and utility to human life including emergency response, wide area efficient communications, and effective transportation. Elements of satellite systems incorporate technologies such as navigation with the global positioning system (GPS), satellite digital video broadcasting, and information transmission with a very small aperture terminal (VSAT), etc. The satellite systems importance is growing in prominence with end users' requirement for globally high data rate transmissions; the cost reduction of launching satellites; development of smaller sized satellites including cubesat, nanosat, picosat, and femtosat; and integrating internet services with satellite networks. However, with the promising benefits, challenges remain to fully develop secure and robust satellite systems with pervasive computing and communications. In this paper, we investigate both cyber security and radio frequency (RF) interferences mitigation for satellite systems, and demonstrate that they are not isolated. The action space for both cyber security and RF interferences are firstly summarized for satellite systems, based on which the mitigation schemes for both cyber security and RF interferences are given. A multi-layered satellite systems structure is provided with cross-layer design considering multi-path routing and channel coding, to provide great security and diversity gains for secure and robust satellite systems.

  14. An implementation of Software Defined Radios for federated aerospace networks: Informing satellite implementations using an inter-balloon communications experiment

    Science.gov (United States)

    Akhtyamov, Rustam; Cruz, Ignasi Lluch i.; Matevosyan, Hripsime; Knoll, Dominik; Pica, Udrivolf; Lisi, Marco; Golkar, Alessandro

    2016-06-01

    Novel space mission concepts such as Federated Satellite Systems promise to enhance sustainability, robustness, and reliability of current missions by means of in-orbit sharing of space assets. This new paradigm requires the utilization of several technologies in order to confer flexibility and re-configurability to communications systems among heterogeneous spacecrafts. This paper illustrates the results of the experimental demonstration of the value proposition of federated satellites through two stratospheric balloons interoperating with a tracking ground station through Commercial Off-The-Shelf Software Defined Radios (SDRs). The paper reports telemetry analysis and characterizes the communications network that was realized in-flight. Furthermore, it provides details on an in-flight anomaly experienced by one of the balloons, which was recovered through the use of the federated technology that has been developed. The anomaly experienced led to the early loss of the directional link from the ground station to the affected stratospheric balloon node after 15 min in flight. Nevertheless, thanks to the federated approach among the systems, the ground station was still able to retrieve the balloon's data in real time through the network system, for which the other balloon operated as a federated relay for 45 min in flight, uninterrupted. In other words, the federated approach to the system allowed triplicating the useful lifetime of the defective system, which would have not been possible to realize otherwise. Such anomaly coincidentally demonstrated the value of the federated approach to space systems design. The paper paves the way for future tests on space assets.

  15. Communication System Architecture for Planetary Exploration

    Science.gov (United States)

    Braham, Stephen P.; Alena, Richard; Gilbaugh, Bruce; Glass, Brian; Norvig, Peter (Technical Monitor)

    2001-01-01

    Future human missions to Mars will require effective communications supporting exploration activities and scientific field data collection. Constraints on cost, size, weight and power consumption for all communications equipment make optimization of these systems very important. These information and communication systems connect people and systems together into coherent teams performing the difficult and hazardous tasks inherent in planetary exploration. The communication network supporting vehicle telemetry data, mission operations, and scientific collaboration must have excellent reliability, and flexibility.

  16. Code-expanded radio access protocol for machine-to-machine communications

    DEFF Research Database (Denmark)

    Thomsen, Henning; Kiilerich Pratas, Nuno; Stefanovic, Cedomir

    2013-01-01

    The random access methods used for support of machine-to-machine, also referred to as Machine-Type Communications, in current cellular standards are derivatives of traditional framed slotted ALOHA and therefore do not support high user loads efficiently. We propose an approach that is motivated...... subframes and orthogonal preambles, the amount of available contention resources is drastically increased, enabling the massive support of Machine-Type Communication users that is beyond the reach of current systems....

  17. New horizons in mobile and wireless communications, v.1 radio interfaces

    CERN Document Server

    Prasad, Ramjee

    2009-01-01

    Based on cutting-edge research projects in the field, this book (part of a comprehensive 4-volume series) provides the latest details and covers the most impactful aspects of mobile, wireless, and broadband communications development. These books present key systems and enabling technologies in a clear and accessible manner, offering you a detailed roadmap the future evolution of next generation communications. Other volumes cover Networks, Services and Applications; Reconfigurability; and Ad Hoc Networks.

  18. Space Telecommunications Radio System (STRS) Application Repository Design and Analysis

    Science.gov (United States)

    Handler, Louis M.

    2013-01-01

    The Space Telecommunications Radio System (STRS) Application Repository Design and Analysis document describes the STRS application repository for software-defined radio (SDR) applications intended to be compliant to the STRS Architecture Standard. The document provides information about the submission of artifacts to the STRS application repository, to provide information to the potential users of that information, and for the systems engineer to understand the requirements, concepts, and approach to the STRS application repository. The STRS application repository is intended to capture knowledge, documents, and other artifacts for each waveform application or other application outside of its project so that when the project ends, the knowledge is retained. The document describes the transmission of technology from mission to mission capturing lessons learned that are used for continuous improvement across projects and supporting NASA Procedural Requirements (NPRs) for performing software engineering projects and NASAs release process.

  19. UNDERSTANDING THE EVOLUTION OF CLOSE BINARY SYSTEMS WITH RADIO PULSARS

    Energy Technology Data Exchange (ETDEWEB)

    Benvenuto, O. G. [Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, 1900 La Plata, Buenos Aires (Argentina); De Vito, M. A. [Instituto de Astrofísica de La Plata (IALP), CCT-CONICET-UNLP. Paseo del Bosque S/N (B1900FWA), La Plata (Argentina); Horvath, J. E., E-mail: obenvenu@fcaglp.unlp.edu.ar, E-mail: adevito@fcaglp.unlp.edu.ar, E-mail: foton@astro.iag.usp.br [Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo R. do Matão 1226 (05508-090), Cidade Universitária, São Paulo SP (Brazil)

    2014-05-01

    We calculate the evolution of close binary systems (CBSs) formed by a neutron star (behaving as a radio pulsar) and a normal donor star, which evolve either to a helium white dwarf (HeWD) or to ultra-short orbital period systems. We consider X-ray irradiation feedback and evaporation due to radio pulsar irradiation. We show that irradiation feedback leads to cyclic mass transfer episodes, allowing CBSs to be observed in between episodes as binary radio pulsars under conditions in which standard, non-irradiated models predict the occurrence of a low-mass X-ray binary. This behavior accounts for the existence of a family of eclipsing binary systems known as redbacks. We predict that redback companions should almost fill their Roche lobe, as observed in PSR J1723-2837. This state is also possible for systems evolving with larger orbital periods. Therefore, binary radio pulsars with companion star masses usually interpreted as larger than expected to produce HeWDs may also result in such quasi-Roche lobe overflow states, rather than hosting a carbon-oxygen WD. We found that CBSs with initial orbital periods of P{sub i} < 1 day evolve into redbacks. Some of them produce low-mass HeWDs, and a subgroup with shorter P{sub i} becomes black widows (BWs). Thus, BWs descend from redbacks, although not all redbacks evolve into BWs. There is mounting observational evidence favoring BW pulsars to be very massive (≳ 2 M {sub ☉}). As they should be redback descendants, redback pulsars should also be very massive, since most of the mass is transferred before this stage.

  20. Large-N correlator systems for low frequency radio astronomy

    Science.gov (United States)

    Foster, Griffin

    Low frequency radio astronomy has entered a second golden age driven by the development of a new class of large-N interferometric arrays. The low frequency array (LOFAR) and a number of redshifted HI Epoch of Reionization (EoR) arrays are currently undergoing commission and regularly observing. Future arrays of unprecedented sensitivity and resolutions at low frequencies, such as the square kilometer array (SKA) and the hydrogen epoch of reionization array (HERA), are in development. The combination of advancements in specialized field programmable gate array (FPGA) hardware for signal processing, computing and graphics processing unit (GPU) resources, and new imaging and calibration algorithms has opened up the oft underused radio band below 300 MHz. These interferometric arrays require efficient implementation of digital signal processing (DSP) hardware to compute the baseline correlations. FPGA technology provides an optimal platform to develop new correlators. The significant growth in data rates from these systems requires automated software to reduce the correlations in real time before storing the data products to disk. Low frequency, widefield observations introduce a number of unique calibration and imaging challenges. The efficient implementation of FX correlators using FPGA hardware is presented. Two correlators have been developed, one for the 32 element BEST-2 array at Medicina Observatory and the other for the 96 element LOFAR station at Chilbolton Observatory. In addition, calibration and imaging software has been developed for each system which makes use of the radio interferometry measurement equation (RIME) to derive calibrations. A process for generating sky maps from widefield LOFAR station observations is presented. Shapelets, a method of modelling extended structures such as resolved sources and beam patterns has been adapted for radio astronomy use to further improve system calibration. Scaling of computing technology allows for the

  1. An atmosphere monitoring system for the Sardinia radio telescope

    Science.gov (United States)

    Buffa, F.; Bolli, P.; Sanna, G.; Serra, G.

    2017-01-01

    The Sardinia radio telescope (SRT) is a new facility managed by the Italian National Institute for Astrophysics (INAF). SRT will detect the extremely faint radio wave signals emitted by astronomical objects in a wide frequency range from decimeter to millimeter wavelengths. Especially at high frequencies (>10 GHz), specific weather conditions and interactions between signal and atmospheric constituents (mainly water and oxygen molecules) affect the radio astronomic observation reducing the antenna performances. Thus, modern ground-based telescopes are usually equipped with systems able to examine in real-time several atmospheric parameters (opacity, integrated water vapor, etc.), and in some cases to forecast the weather conditions (wind, rain, snow, etc.), in order to ensure the antenna safety and support the schedule of the telescope observations. Here, we describe the atmosphere monitoring system (AMS) realized with the aim to improve the SRT operative efficiency. It consists of a network of different sensors such as radiometers, radiosondes, weather stations, GPS and some well-established weather models. After a validation of the scheme, we successfully tested the AMS in two real practical scenarios, comparing the AMS outcomes with those of independent techniques. In the first one we were able to detect an incoming storm front applying different techniques (GPS, radiometer and the weather forecast model), while in the last one we modeled the SRT antenna system temperature at 22 GHz processing the AMS data set.

  2. Do Animal Communication Systems Have Phonemes?

    Science.gov (United States)

    Bowling, Daniel L; Fitch, W Tecumseh

    2015-10-01

    Biologists often ask whether animal communication systems make use of conceptual entities from linguistics, such as semantics or syntax. A new study of an Australian bird species argues that their communication system has phonemes, but we argue that imposing linguistic concepts obscures, rather than clarifyies, communicative function. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Collective Review: Catalyzing Sustainable Social Change through Public Communication, Radio for Development, and Participatory Monitoring and Evaluation

    Directory of Open Access Journals (Sweden)

    Levi Zeleza Manda

    2014-07-01

    Full Text Available This article reviews three recent books by four authors (two single, one joint from Australia and Africa. The three books are related in that they all discuss the need to acknowledge the role of dialogic communication and popular participation as catalysts for sustainable social development in the developing world. Specifically, "Public Relations, Activism and Social Change" proposes that public relations (PR needs to transform itself into public communication (PC, where people are made to make decisions based on dialogue and the correctness of the information rather than out of manipulative propaganda. "People's Radio" argues that radio can lead to tangible and long-lasting social change if it engages the primary beneficiaries in the planning, production presentation of the programs and management of (community radio stations. "Evaluating Communication for Development" argues that through indicators defined by the local people themselves, evaluators can find evidence of social change brought about by communication for development activities. The book suggests that to be effective, monitoring and evaluation of communication for development ought to be participatory and use qualitative data collection tools such as focus groups, in-depth interviews, and most significant change (MSC evaluations. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs140383

  4. Common Submarine Radio Room: A Case Study of a System of Systems Approach

    Science.gov (United States)

    2014-09-01

    International Standards Organization ( ISO ) 9000/ 9001 standards. Since 2008 the CSRR program completed six projects and SSC LANT another 15 related to...104 F. COMMON SUBMARINE RADIO ROOM SYSTEM OF SYSTEMS TRAINING APPROACH...111 3. Training ............................................................................................113 4. Production

  5. Modeling of digital communication systems using SIMULINK

    CERN Document Server

    Giordano, Arthur A

    2015-01-01

    Arthur Giordano, PhD, is a consultant in the field of military and commercial communications specializing in wireless communications. He is a co-founder of G5 Scientific, LLC, is a senior member of the IEEE and has taught graduate communications courses. He has developed numerous models using MathWorks®' SIMULINK®® to characterize digital communications systems. Allen Levesque, PhD, is a consultant specializing in digital communications systems, and is a partner in G5 Scientific, LLC. He has taught graduate courses in digital communications at Worcester Polytechnic Institute and is currently

  6. Computer controls of the CERN PS radio-frequency system

    Energy Technology Data Exchange (ETDEWEB)

    Benincasa, G.P.; Garoby, R.

    1986-06-01

    The PS computer control project has recently been terminated with the integration of the radio-frequency system. While the general controls frame was used, special software and hardware solutions were also necessary to cope with the peculiarities of the RF system. After a brief description of both the RF process and the PS control system, this paper recalls the various operational requirements and real-time constraints and relates on the criteria and methods followed during the design phase. Some implementation is illustrated with emphasis on diagnostics and measurements.

  7. Computer controls of the CERN PS radio-frequency system

    Science.gov (United States)

    Benincasa, G. P.; Garoby, R.

    1986-06-01

    The PS computer control project has recently been terminated with the integration of the radio-frequency system. While the general controls frame was used, special software and hardware solutions were also necessary to cope with the peculiarities of the rf system. After a brief description of both the rf process and the PS control system, this paper recalls the various operational requirements and real-time constraints and relates on the criteria and methods followed during the design phase. Some implementation is illustrated with emphasis on diagnostics and measurements.

  8. Advances in communication systems and electrical engineering

    CERN Document Server

    Huang, Xu

    2008-01-01

    This volume contains contributions from participants in the 2007 International Multiconference of Engineers and Computer Scientists Topics covered include communications theory, communications protocols, network management, wireless networks, telecommunication, electronics, power engineering, control engineering, signal processing, and industrial applications. The book will offer the states of arts of tremendous advances in communication systems and electrical engineering and also serve as an excellent reference work for researchers and graduate students working with/on communication systems a

  9. Considerations for the Next Revision of NASA's Space Telecommunications Radio System Architecture

    Science.gov (United States)

    Johnson, Sandra K.; Handler, Louis M.; Briones, Janette C.

    2016-01-01

    Development of NASA's Software Defined Radio architecture, the Space Telecommunication Radio System (STRS), was initiated in 2004 with a goal of reducing the cost, risk and schedule when implementing Software Defined Radios (SDR) for National Aeronautics and Space Administration (NASA) space missions. Since STRS was first flown in 2012 on three Software Defined Radios on the Space Communication and Navigation (SCaN) Testbed, only minor changes have been made to the architecture. Multiple entities have since implemented the architecture and provided significant feedback for consideration for the next revision of the standard. The focus for the first set of updates to the architecture is items that enhance application portability. Items that require modifications to existing applications before migrating to the updated architecture will only be considered if there is compelling reasons to make the change. The significant suggestions that were further evaluated for consideration include expanding and clarifying the timing Application Programming Interfaces (APIs), improving handle name and identification (ID) definitions and use, and multiple items related to implementation of STRS Devices. In addition to ideas suggested while implementing STRS, SDR technology has evolved significantly and this impact to the architecture needs to be considered. These include incorporating cognitive concepts - learning from past decisions and making new decisions that the radio can act upon. SDRs are also being developed that do not contain a General Purpose Module - which is currently required for the platform to be STRS compliant. The purpose of this paper is to discuss the comments received, provide a summary of the evaluation considerations, and examine planned dispositions.

  10. Conception d'un crypto-système reconfigurable pour la radio logicielle sécurisée

    OpenAIRE

    Grand, Michael

    2011-01-01

    The research detailed in this document deal with the design and implementation of a hardware integrated circuit intended to be used as a cryptographic sub-system in secure software defined radios. Since the early 90's, radio systems have gradually evolved from traditional radio to software defined radio. Improvement of the software defined radio has enabled the integration of an increasing number of communication standards on a single radio device. The designer of a software defined radio fac...

  11. Design and Performance of the ARIANNA Hexagonal Radio Array Systems

    CERN Document Server

    Barwick, S W; Besson, D Z; Cheim, E; Duffin, T; Hanson, J C; Klein, S R; Kleinfelder, S A; Prakash, T; Piasecki, M; Ratzlaff, K; Reed, C; Roumi, M; Samanta, A; Stezelberger, T; Tatar, J; Walker, J; Young, R; Zou, L

    2014-01-01

    We report on the development, installation and operation of the first three of seven stations deployed at the ARIANNA site's pilot Hexagonal Radio Array in Antarctica. The primary goal of the ARIANNA project is to observe ultra-high energy (>100 PeV) cosmogenic neutrino signatures using a large array of autonomous stations each dispersed 1 km apart on the surface of the Ross Ice Shelf. Sensing radio emissions of 100 MHz to 1 GHz, each station in the array contains RF antennas, amplifiers, 1.92 G-sample/s, 850 MHz bandwidth signal acquisition circuitry, pattern-matching trigger capabilities, an embedded CPU, 32 GB of solid-state data storage, and long-distance wireless and satellite communications. Power is provided by the sun and LiFePO4 storage batteries, and the stations consume an average of 7W of power. Operation on solar power has resulted in >=58% per calendar-year live-time. The station's pattern-trigger capabilities reduce the trigger rates to a few milli-Hertz with 4-sigma thresholds while retaining ...

  12. Ergodic Capacity Analysis in Cognitive Radio Systems under Channel Uncertainty

    CERN Document Server

    Akin, Sami

    2010-01-01

    In this paper, pilot-symbol-assisted transmission in cognitive radio systems over time selective flat fading channels is studied. It is assumed that causal and noncausal Wiener filter estimators are used at the secondary receiver with the aid of training symbols to obtain the channel side information (CSI) under an interference power constraint. Cognitive radio model is described together with detection and false alarm probabilities determined by using a Neyman-Person detector for channel sensing. Subsequently, for both filters, the variances of estimate errors are calculated from the Doppler power spectrum of the channel, and achievable rate expressions are provided considering the scenarios which are results of channel sensing. Numerical results are obtained in Gauss-Markov modeled channels, and achievable rates obtained by using causal and noncausal filters are compared and it is shown that the difference is decreasing with increasing signal-to-noise ratio (SNR). Moreover, the optimal probability of detect...

  13. Unmanned Aircraft System Control and ATC Communications Bandwidth Requirements

    Science.gov (United States)

    Henriksen, Steve

    2008-01-01

    There are significant activities taking place to establish the procedures and requirements for safe and routine operation of unmanned aircraft systems (UAS) in the National Airspace System (NAS). Among the barriers to overcome in achieving this goal is the lack of sufficient frequency spectrum necessary for the UAS control and air traffic control (ATC) communications links. This shortcoming is compounded by the fact that the UAS control communications links will likely be required to operate in protected frequency spectrum, just as ATC communications links are, because they relate to "safety and regularity of flight." To support future International Telecommunications Union (ITU) World Radio Conference (WRC) agenda items concerning new frequency allocations for UAS communications links, and to augment the Future Communications Study (FCS) Technology Evaluation Group efforts, NASA Glenn Research Center has sponsored a task to estimate the UAS control and ATC communications bandwidth requirements for safe, reliable, and routine operation of UAS in the NAS. This report describes the process and results of that task. The study focused on long-term bandwidth requirements for UAS approximately through 2030.

  14. Radio broadcasting via satellite

    Science.gov (United States)

    Helm, Neil R.; Pritchard, Wilbur L.

    1990-10-01

    Market areas offering potential for future narrowband broadcast satellites are examined, including international public diplomacy, government- and advertising-supported, and business-application usages. Technical issues such as frequency allocation, spacecraft types, transmission parameters, and radio receiver characteristics are outlined. Service and system requirements, advertising revenue, and business communications services are among the economic issues discussed. The institutional framework required to provide an operational radio broadcast service is studied, and new initiatives in direct broadcast audio radio systems, encompassing studies, tests, in-orbit demonstrations of, and proposals for national and international commercial broadcast services are considered.

  15. New Military Strategic Communications System

    Science.gov (United States)

    2007-05-01

    54 O’Day, 6. 55 Perlmutter, David D. The Manship School guide to Political Communication . Louisiana State University Press...Westport: Praeger Publishing, 2006. Perlmutter, David D. The Manship School guide to Political Communication . Louisiana State University Press

  16. An RF tag communication system model for noise radar

    Science.gov (United States)

    Pan, Qihe; Narayanan, Ram M.

    2008-04-01

    RF (radio-frequency) tags have drawn increasing research interest because of their great potential uses in many radio frequency identification applications. They can also be configured to work with radar as a communication channel by receiving radar acquisition signals, suitably coding these, and retransmitting them back to the radar. This paper proposes a system model for the communication between a noise radar and multiple RF tags. The radar interrogates the RF tags in a region of interest by sending ultrawideband noise signals. Upon receiving the radar's signal, all the tags within the radar's range wake up, and respond to the radar with simple messages. The RF tag filters the radar signal to a unique spectral band, which represents its identification information, and different RF tags occupy different non-overlapping bands of the spectrum of the radar signal. Tag messages are modulated onto the waveform through taps of weighted delays. The radar decodes the RF tag identifications and corresponding messages by cross-correlating the RF tag returned signals with the replica of the radar transmitted signal. Calculations and simulation results both show that the proposed system is capable of communicating simple messages between RF tags and radar.

  17. Smart Grid Communications System Blueprint

    Science.gov (United States)

    Clark, Adrian; Pavlovski, Chris

    2010-10-01

    Telecommunications operators are well versed in deploying 2G and 3G wireless networks. These networks presently support the mobile business user and/or retail consumer wishing to place conventional voice calls and data connections. The electrical power industry has recently commenced transformation of its distribution networks by deploying smart monitoring and control devices throughout their networks. This evolution of the network into a `smart grid' has also motivated the need to deploy wireless technologies that bridge the communication gap between the smart devices and information technology systems. The requirements of these networks differ from traditional wireless networks that communications operators have deployed, which have thus far forced energy companies to consider deploying their own wireless networks. We present our experience in deploying wireless networks to support the smart grid and highlight the key properties of these networks. These characteristics include application awareness, support for large numbers of simultaneous cell connections, high service coverage and prioritized routing of data. We also outline our target blueprint architecture that may be useful to the industry in building wireless and fixed networks to support the smart grid. By observing our experiences, telecommunications operators and equipment manufacturers will be able to augment their current networks and products in a way that accommodates the needs of the emerging industry of smart grids and intelligent electrical networks.

  18. Talk radio as the soundtrack of our lives: Participatory HIV/AIDS communication, public self-expression and Positive Talk.

    Science.gov (United States)

    Burger, Mariekie

    2015-01-01

    Despite the many HIV/AIDS communication initiatives, combined with support and infrastructural support in South Africa, risky behaviour associated with the spread of the epidemic is increasing amongst many groups. This calls for a re-evaluation of endeavours aimed at curbing the spread of the epidemic. This article is only concerned with the communicational aspects of the epidemic, but does not negate the interaction of these with other measures taken to address the epidemic. As is the case with most health communication initiatives, HIV/AIDS communication initiatives have evolved to favour the participatory approach above one-directional transmission of information to the public. The participatory approach rests on the assumption that an HIV/AIDS communication initiative stands the best chance of resulting in behaviour change if members of the target community participate in the communication initiative. The assumption is that as many people as possible should be involved in the maximum number of phases of the communicative initiative (such as initial research, planning, implementation and evaluation of the project). Some research has recently started to explore new forms of community participation, including inviting community participation through, for example, internet-based platforms such as social media, and mobile phone platforms such as WhatsApp and BBM. However, the reality broadcast genre--more specifically, talk radio--has been neglected, as only a few research investigations focused on talk radio and most of these are not exclusively about HIV/AIDS communication but focus on other health topics. From a participatory communication perspective, two sets of critique against the existing HIV/AIDS communication projects hold water: firstly, they do not make the maximum use of participatory communication principles and, secondly, they are externally initiated projects and emanate from outside the target community. To address both of these concerns, this

  19. Reliable Radio Access for Massive Machine-to-Machine (M2M) Communication

    DEFF Research Database (Denmark)

    Madueño, Germán Corrales

    Machine-to-Machine (M2M) communication is a term that identifies the emerging paradigm of interconnected systems, machines, and things that communicate and collaborate without human intervention. The characteristics of M2M Communications are small payloads and sporadic transmissions, while...... the service requirements can range from massive number of devices to ultra-reliable. This PhD thesis focuses on novel mechanisms to meet these requirements in a variety of wireless systems, from well-established technologies such as cellular networks, to emerging technologies like IEEE 802.11ah. Today...... an overwhelming 89% of the deployed M2M modules are GPRS-based. This motivates us to investigate the potential of GPRS as a dedicated M2M network. We show that by introducing minimal modifications to GPRS operation, a large number of devices can be reliably supported. Surprisingly, even though LTE is seen...

  20. A randomized model for communicating embedded systems

    NARCIS (Netherlands)

    Bujorianu, M.C.; Bujorianu, L.M.

    2008-01-01

    Nowadays, there is an intense research activity in designing systems that operate in real life, physical environments. This research is spanned by various areas in computer science and engineering: embedded systems, reactive systems, wireless communications, hybrid systems, stochastic processes, etc

  1. Expert Systems as Tools for Technical Communicators.

    Science.gov (United States)

    Grider, Daryl A.

    1994-01-01

    Discusses expertise, what an expert system is, what an expert system shell is, what expert systems can and cannot do, knowledge engineering and technical communicators, and planning and managing expert system projects. (SR)

  2. A randomized model for communicating embedded systems

    NARCIS (Netherlands)

    Bujorianu, M.C.; Bujorianu, L.M.

    2008-01-01

    Nowadays, there is an intense research activity in designing systems that operate in real life, physical environments. This research is spanned by various areas in computer science and engineering: embedded systems, reactive systems, wireless communications, hybrid systems, stochastic processes,

  3. Radio frequency science considerations. [technology utilization of telecommunications system

    Science.gov (United States)

    Croft, T. A.

    1974-01-01

    Use of the 400 MHz telecommunications system to obtain scientific information, to provide backup information for the experiments flown, and to obtain measurements which aid in designing future probes is considered. Recommended objectives of such a program are summarized and include: measure 400 MHz amplitude to determine adsorption and perhaps scintillation (if data rate permits); measure noise strength near 400 MHz to reexamine 400 MHz choice and to observe thermal, cosmic, and local synchrotron noise trends; probe VSWR sensing to monitor integrity of system, icing, and possible plasma effects; after the probe is finished, have the bus radio occultation in the same region where the probe fell to evaluate the occultation.

  4. INTEGRATING RADIO FREQUENCY IDENTIFICATION TECHNOLOGY IN ACADEMIC MANAGEMENT SYSTEM

    Directory of Open Access Journals (Sweden)

    Zainab Rasheed Mirza

    2014-01-01

    Full Text Available The purpose of this study is building a web and windows based intelligent system using web technologies, biometric and Radio Frequency Identification technologies (RFID to strengthen an Academic Management System (AMS in a campus for monitoring and improving academic performance of teachers and students. A campus mobile phone application will allow guardians to monitor student’s movement history at campus, e-payments and food choices at canteen, class attendance, exam attendance and academic performance on daily basis. Mobile application for students will allow students to view their class schedules, teacher appointments, e-payment statement, warnings or announcements, locate their exam halls and search for classrooms.

  5. Dual-Stack Single-Radio Communication Architecture for UAV Acting As a Mobile Node to Collect Data in WSNs

    Science.gov (United States)

    Sayyed, Ali; Medeiros de Araújo, Gustavo; Bodanese, João Paulo; Buss Becker, Leandro

    2015-01-01

    The use of mobile nodes to collect data in a Wireless Sensor Network (WSN) has gained special attention over the last years. Some researchers explore the use of Unmanned Aerial Vehicles (UAVs) as mobile node for such data-collection purposes. Analyzing these works, it is apparent that mobile nodes used in such scenarios are typically equipped with at least two different radio interfaces. The present work presents a Dual-Stack Single-Radio Communication Architecture (DSSRCA), which allows a UAV to communicate in a bidirectional manner with a WSN and a Sink node. The proposed architecture was specifically designed to support different network QoS requirements, such as best-effort and more reliable communications, attending both UAV-to-WSN and UAV-to-Sink communications needs. DSSRCA was implemented and tested on a real UAV, as detailed in this paper. This paper also includes a simulation analysis that addresses bandwidth consumption in an environmental monitoring application scenario. It includes an analysis of the data gathering rate that can be achieved considering different UAV flight speeds. Obtained results show the viability of using a single radio transmitter for collecting data from the WSN and forwarding such data to the Sink node. PMID:26389911

  6. Dual-Stack Single-Radio Communication Architecture for UAV Acting As a Mobile Node to Collect Data in WSNs.

    Science.gov (United States)

    Sayyed, Ali; de Araújo, Gustavo Medeiros; Bodanese, João Paulo; Becker, Leandro Buss

    2015-09-16

    The use of mobile nodes to collect data in a Wireless Sensor Network (WSN) has gained special attention over the last years. Some researchers explore the use of Unmanned Aerial Vehicles (UAVs) as mobile node for such data-collection purposes. Analyzing these works, it is apparent that mobile nodes used in such scenarios are typically equipped with at least two different radio interfaces. The present work presents a Dual-Stack Single-Radio Communication Architecture (DSSRCA), which allows a UAV to communicate in a bidirectional manner with a WSN and a Sink node. The proposed architecture was specifically designed to support different network QoS requirements, such as best-effort and more reliable communications, attending both UAV-to-WSN and UAV-to-Sink communications needs. DSSRCA was implemented and tested on a real UAV, as detailed in this paper. This paper also includes a simulation analysis that addresses bandwidth consumption in an environmental monitoring application scenario. It includes an analysis of the data gathering rate that can be achieved considering different UAV flight speeds. Obtained results show the viability of using a single radio transmitter for collecting data from the WSN and forwarding such data to the Sink node.

  7. Dual-Stack Single-Radio Communication Architecture for UAV Acting As a Mobile Node to Collect Data in WSNs

    Directory of Open Access Journals (Sweden)

    Ali Sayyed

    2015-09-01

    Full Text Available The use of mobile nodes to collect data in a Wireless Sensor Network (WSN has gained special attention over the last years. Some researchers explore the use of Unmanned Aerial Vehicles (UAVs as mobile node for such data-collection purposes. Analyzing these works, it is apparent that mobile nodes used in such scenarios are typically equipped with at least two different radio interfaces. The present work presents a Dual-Stack Single-Radio Communication Architecture (DSSRCA, which allows a UAV to communicate in a bidirectional manner with a WSN and a Sink node. The proposed architecture was specifically designed to support different network QoS requirements, such as best-effort and more reliable communications, attending both UAV-to-WSN and UAV-to-Sink communications needs. DSSRCA was implemented and tested on a real UAV, as detailed in this paper. This paper also includes a simulation analysis that addresses bandwidth consumption in an environmental monitoring application scenario. It includes an analysis of the data gathering rate that can be achieved considering different UAV flight speeds. Obtained results show the viability of using a single radio transmitter for collecting data from the WSN and forwarding such data to the Sink node.

  8. Wireless radio a history

    CERN Document Server

    Coe, Lewis

    2006-01-01

    ""Informative...recommended""--Choice; ""interesting...a good read...well worth reading""--Contact Magazine. This history first looks at Marconi's wireless communications system and then explores its many applications, including marine radio, cellular telephones, police and military uses, television and radar. Radio collecting is also discussed, and brief biographies are provided for the major figures in the development and use of the wireless.

  9. Wireless Augmented Reality Communication System

    Science.gov (United States)

    Devereaux, Ann (Inventor); Jedrey, Thomas (Inventor); Agan, Martin (Inventor)

    2017-01-01

    A portable unit is for video communication to select a user name in a user name network. A transceiver wirelessly accesses a communication network through a wireless connection to a general purpose node coupled to the communication network. A user interface can receive user input to log on to a user name network through the communication network. The user name network has a plurality of user names, at least one of the plurality of user names is associated with a remote portable unit, logged on to the user name network and available for video communication.

  10. Transition From NASA Space Communication Systems to Commerical Communication Products

    Science.gov (United States)

    Ghazvinian, Farzad; Lindsey, William C.

    1994-01-01

    Transitioning from twenty-five years of space communication system architecting, engineering and development to creating and marketing of commercial communication system hardware and software products is no simple task for small, high-tech system engineering companies whose major source of revenue has been the U.S. Government. Yet, many small businesses are faced with this onerous and perplexing task. The purpose of this talk/paper is to present one small business (LinCom) approach to taking advantage of the systems engineering expertise and knowledge captured in physical neural networks and simulation software by supporting numerous National Aeronautics and Space Administration (NASA) and the Department of Defense (DoD) projects, e.g., Space Shuttle, TDRSS, Space Station, DCSC, Milstar, etc. The innovative ingredients needed for a systems house to transition to a wireless communication system products house that supports personal communication services and networks (PCS and PCN) development in a global economy will be discussed. Efficient methods for using past government sponsored space system research and development to transition to VLSI communication chip set products will be presented along with notions of how synergy between government and industry can be maintained to benefit both parties.

  11. Distribution system protection with communication technologies

    DEFF Research Database (Denmark)

    Wei, Mu; Chen, Zhe

    2010-01-01

    Due to the communication technologies’ involvement in the distribution power system, the time-critical protection function may be implemented more accurately, therefore distribution power systems’ stability, reliability and security could be improved. This paper presents an active distribution...... power system, including CHPs (Combined Heating and Power) and small scaled WTs (Wind Turbines), as a practical example to examine the possible impacts of communication technologies on the power system. Under some fault scenarios, the power system’s responses to the fault are compared between the system...... with communication technologies and that without communication technologies. At the same time, the previously proposed study method of combining the simulations of communication and power systems is adopted in this study. The performance of a communication network adopted for power system is simulated by OPNET...

  12. FLYCON-R: Wireless Integrated Communication and Navigation System

    Science.gov (United States)

    Palomo, Jose Maria; Gomez de Aguero, Sergio; Latorre, Antonio; Fernandez, Antonio; Pina, Fernando; Tarziu, Andrei; Balan, Mugurel; Sanchez Gestido, Manuel; Concari, Paolo

    2015-09-01

    This paper presents the FLYCON-R system, which is an integrated communication and ranging system based on OFDM signal. FLYCON-R supports high data rates and flexible data communications, providing also relative ranging measurements based on Time of Arrival (ToA) from the Radio Frequency signals. Deimos Space (Spain and Romania) and ISS are carrying out the FLYCON-R project for ESA under the Romanian task force initiative. FLYCON-R (Prototype of Integrated Nav-Com sensor based on WiMax Standard for Formation Flying) aims to upgrade the previously existing FLYCON proof of concept (PoC) to a more advanced, elegant breadboard version, ready for on-ground flight testing and as near as possible to a future flight version. The paper presents as well the preliminary results of the flight tests performed on the Spanish R&D PERIGEO project, using the FLYCON PoC prototypes.

  13. Communication Systems and Study Method for Active Distribution Power systems

    DEFF Research Database (Denmark)

    Wei, Mu; Chen, Zhe

    Due to the involvement and evolvement of communication technologies in contemporary power systems, the applications of modern communication technologies in distribution power system are becoming increasingly important. In this paper, the International Organization for Standardization (ISO....... The suitability of the communication technology to the distribution power system with active renewable energy based generation units is discussed. Subsequently the typical possible communication systems are studied by simulation. In this paper, a novel method of integrating communication system impact into power...... system simulation is presented to address the problem of lack of off-shelf research tools on the power system communication. The communication system is configured and studied by the OPNET, and the performance of an active distribution power system integrated with the communication system is simulated...

  14. COMMUNICATIONS

    CERN Multimedia

    L. Taylor and D. Barney

    2010-01-01

    CMS Centres, Outreach and the 7 TeV Media Event The new CMS Communications group is now established and is addressing three areas that are critical to CMS as it enters the physics operations phase: - Communications Infrastructure, including almost 50 CMS Centres Worldwide, videoconferencing systems, and CERN meeting rooms - Information systems, including the internal and external Web sites as well as the document preparation and management systems - Outreach and Education activities, including working with print, radio and TV media, visits to CMS, and exhibitions. The group has been active in many areas, with the highest priority being accorded to needs of CMS operations and preparations for the major media event planned for 7 TeV collisions. Unfortunately the CMS Centre@CERN suffered a major setback when, on 21st December, a cooling water pipe froze and burst on the floor above the CMS Centre main room. Water poured through the ceiling, flooding the floor and soaking some of the consoles, before e...

  15. 33 CFR 127.111 - Communications systems.

    Science.gov (United States)

    2010-07-01

    ...) WATERFRONT FACILITIES WATERFRONT FACILITIES HANDLING LIQUEFIED NATURAL GAS AND LIQUEFIED HAZARDOUS GAS Waterfront Facilities Handling Liquefied Natural Gas § 127.111 Communications systems. (a) The...

  16. Multistandard Radio Systems: State of the Art and Research Issues

    DEFF Research Database (Denmark)

    Zakrzewska, Anna; Berger, Michael Stübert; Ruepp, Sarah Renée

    2010-01-01

    Integration of various wireless standards and building one consistent and compatible broadband system is a trend in wireless communication nowadays. This work focuses on multistandard networks enabling the cooperation between LTE and WiMAX systems. It presents the general vision on multistandard...

  17. A Single Hidden Layered Fuzzy Back propagation Algorithm for Joint Radio Resource Management in Radio Access Systems

    Directory of Open Access Journals (Sweden)

    J.Preethi

    2010-07-01

    Full Text Available In this paper, we propose a single hidden layered fuzzy neural algorithm, which is able to provide a better quality of service constraints in a multi-cell scenario with three different radio access technologies (RATs namely the Universal Mobile Telecommunication Systems (UMTS, the Wireless Local Area Network (WLAN and the Global System for Mobile Telecommunication (GSM /Enhanced Data rate for GSM Evolution (EDGE Radio access Network (GERAN. This proposed algorithm works in two steps; the first step is to select a suitable combination of cells among the three different RATs. The second step chooses the most appropriate RAT to which the users can be attached and to choose the suitable bandwidth to allocate for the users. The Joint Radio Resource Management (JRRM makes use of fuzzy neural approach to manage dynamically the allocation and deallocation of the different radio resources among thedifferent radio access systems for spectrum bands allocated to each of these systems. By simulation results, we have shown that the proposed algorithm selects the most appropriate RAT in a multi-cell scenario.

  18. Acoustic Communications Measurement Systems (ACOMMS)

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Design and develop adaptive signal processing techniques to improve underwater acoustic communications and networking. Phase coherent and incoherent signal...

  19. How do communication systems emerge?

    Science.gov (United States)

    Scott-Phillips, Thomas C; Blythe, Richard A; Gardner, Andy; West, Stuart A

    2012-05-22

    Communication involves a pair of behaviours--a signal and a response--that are functionally interdependent. Consequently, the emergence of communication involves a chicken-and-egg problem: if signals and responses are dependent on one another, then how does such a relationship emerge in the first place? The empirical literature suggests two solutions to this problem: ritualization and sensory manipulation; and instances of ritualization appear to be more common. However, it is not clear from a theoretical perspective why this should be the case, nor if there are any other routes to communication. Here, we develop an analytical model to examine how communication can emerge. We show that: (i) a state of non-interaction is evolutionarily stable, and so communication will not necessarily emerge even when it is in both parties' interest; (ii) the conditions for sensory manipulation are more stringent than for ritualization, and hence ritualization is likely to be more common; and (iii) communication can arise by a third route, when the intention to communicate can itself be communicated, but this may be limited to humans. More generally, our results demonstrate the utility of a functional approach to communication.

  20. Highly sensitive passive radio frequency identification based sensor systems.

    Science.gov (United States)

    Wissenwasser, J; Vellekoop, M; Heer, R

    2010-02-01

    A novel platform for sensor applications based on radio frequency (rf) identification technology, where passive tags are powered by the rf-field of a reader, is presented. The sophisticated energy harvesting system of the tag enables a blanking of the rf-field for a defined period, while supplying the tag electronics with a highly stable voltage and a power of 25 mW for 100 ms. During this time, span measurements can be performed without interferences of the rf-field. The presented tags work without batteries and are designed for impedance measurements on microbiological cell cultures under physiological relevant conditions as well as in harsh environments.

  1. Highly sensitive passive radio frequency identification based sensor systems

    Science.gov (United States)

    Wissenwasser, J.; Vellekoop, M.; Heer, R.

    2010-02-01

    A novel platform for sensor applications based on radio frequency (rf) identification technology, where passive tags are powered by the rf-field of a reader, is presented. The sophisticated energy harvesting system of the tag enables a blanking of the rf-field for a defined period, while supplying the tag electronics with a highly stable voltage and a power of 25 mW for 100 ms. During this time, span measurements can be performed without interferences of the rf-field. The presented tags work without batteries and are designed for impedance measurements on microbiological cell cultures under physiological relevant conditions as well as in harsh environments.

  2. Computational Interpersonal Communication: Communication Studies and Spoken Dialogue Systems

    Directory of Open Access Journals (Sweden)

    David J. Gunkel

    2016-09-01

    Full Text Available With the advent of spoken dialogue systems (SDS, communication can no longer be considered a human-to-human transaction. It now involves machines. These mechanisms are not just a medium through which human messages pass, but now occupy the position of the other in social interactions. But the development of robust and efficient conversational agents is not just an engineering challenge. It also depends on research in human conversational behavior. It is the thesis of this paper that communication studies is best situated to respond to this need. The paper argues: 1 that research in communication can supply the information necessary to respond to and resolve many of the open problems in SDS engineering, and 2 that the development of SDS applications can provide the discipline of communication with unique opportunities to test extant theory and verify experimental results. We call this new area of interdisciplinary collaboration “computational interpersonal communication” (CIC

  3. A staged model of communication effects: evidence from an entertainment-education radio soap opera in Tanzania.

    Science.gov (United States)

    Vaughan, P W; Rogers, E M

    2000-01-01

    The authors draw on (1) the hierarchy-of-effects (HOE) model, (2) the stages-of-change (SOC) model, (3) social learning theory (SLT), and (4) the diffusion of innovations (DOI) to synthesize a staged model through which communication messages have effects on individual behavior change by stimulating (1) involvement with media characters and role modeling of their actions, and (2) interpersonal communication. Data from a field experiment in Tanzania on the effects of an entertainment-education radio soap opera, Twende na Wakati (Let's Go With the Times), on the adoption of family planning, are analyzed in light of a six-staged model of communication effects. It is found that (1) the model provides a useful framework for understanding the effects of an entertainment-education program, and (2) the radio soap opera promoted progress through the stages for family planning adoption in the treatment area in three of the four years of broadcast, and in the comparison area after broadcasts of the radio program began there.

  4. A 60GHz RoF(radio-over-fiber) transmission system based on PM modulator

    Science.gov (United States)

    Wang, Xin; Liu, Yi; Wang, Wen-Ting

    2016-11-01

    As one of the most important applications of microwave photonic ROF (Radio over Fiber) system which combines the advantages of optical communication and wireless communication is a good candidate for broadband mobile Communication In this paper, we built and simulation a 60GHz RoF(Radio-over-Fiber) transmission system based on PM modulator. First, we introduce the PM-IM(Phase modulation to intensity modulation) modulation mechanisms by the breaking the phase balanced approach. This method solves the problem that the constant envelope (phase modulation signal) generated by the phase modulator can not be directly detected by a photo detector. A standard single-mode fiber (SMF) is connected input to the F-P(Fabry-Perot) optical filter, which is to achieve the PM-IM modulation conversion by changing the wavelength of the laser or the frequency of the modulation factor of the F-P optical filter to adapt to different fiber lengths and the signal transmission rate. These two methods which changing the phase relationship between the optical carrier and the optical side band can realize the ideal phase transition to obtain efficient and low loss modulation conversion. Finally, the simulation results show that different fiber lengths and the signal transmission rate configuration of different wavelength of the laser or the frequency of the modulation factor of the F-P optical filter, the BER performance and the eye diagram of the 60GHz RoF transmission system signals have been improved based on these PM-IM modulation methods.

  5. Simultaneous optical carrier and radio frequency re-modulation in radio-over-fiber systems employing reflective SOA modulators

    DEFF Research Database (Denmark)

    Kassar, Carvalho; Calabretta, Nicola; Tafur Monroy, Idelfonso

    2007-01-01

    We demonstrate an innovative full-duplex radio-over-fibre transmission system employing a reflective SOA to perform simultaneous reusing of the optical carrier and data re-modulation, thus avoiding the use of local radiofrequency oscillator at the station sites.......We demonstrate an innovative full-duplex radio-over-fibre transmission system employing a reflective SOA to perform simultaneous reusing of the optical carrier and data re-modulation, thus avoiding the use of local radiofrequency oscillator at the station sites....

  6. Virtualization of Wireless Communication Systems and Its Maximal Ratio Combining Macrodiversity To Extend CDMA Capacity

    Institute of Scientific and Technical Information of China (English)

    王际兵; 赵明; 周世东; 姚彦

    2001-01-01

    The concept of virtualization of wireless communication systemsis based on the open and scalable hardware platform of software radios in the personal communication network. The base station is divided into four components according to their functions: antenna, IF, baseband, and control, which are connected by the ATM network. Virtualization provides great benefits such as fast handoff and easy realization of different macrodiversity algorithms. Macrodiversity can not be easily realized in conventional cellular systems. An exact analysis is presented for the performance of maximal ratio combining (MRC) macrodiversity in virtualized wireless communication systems. The results show that compared with soft handoff in CDMA systems, MRC can greatly increase the reverse link capacity.

  7. Enhanced UWB Radio Channel Model for Short-Range Communication Scenarios Including User Dynamics

    DEFF Research Database (Denmark)

    Kovacs, Istvan Zsolt; Nguyen, Tuan Hung; Eggers, Patrick Claus F.

    2005-01-01

    In this paper we propose a SISO UWB radio channel model for short-range radio link scenarios between a fixed device and a dynamic user hand-held device. The channel model is derived based on novel experimental UWB radio propagation investigations carried out in typical indoor PAN scenarios...... including realistic device and user terminal antenna configurations. The radio channel measurements have been performed in the lower UWB frequency band of 3GHz to 5GHz with a 2x4 MIMO antenna configuration. Several environments, user scenarios and two types of user terminals have been used. The developed...

  8. Phase-Modulated Optical Communication Systems

    CERN Document Server

    Ho, Keang-Po

    2005-01-01

    Fiber-optic communication systems have revolutionized our telecommunication infrastructures – currently, almost all telephone land-line, cellular, and internet communications must travel via some form of optical fibers. In these transmission systems, neither the phase nor frequency of the optical signal carries information – only the intensity of the signal is used. To transmit more information in a single optical carrier, the phase of the optical carrier must be explored. As a result, there is renewed interest in phase-modulated optical communications, mainly in direct-detection DPSK signals for long-haul optical communication systems. When optical amplifiers are used to maintain certain signal level among the fiber link, the system is limited by amplifier noises and fiber nonlinearities. Phase-Modulated Optical Communication Systems surveys this newly popular area, covering the following topics: The transmitter and receiver for phase-modulated coherent lightwave systems Method for performance analysis o...

  9. Systems and Methods for Radar Data Communication

    Science.gov (United States)

    Bunch, Brian (Inventor); Szeto, Roland (Inventor); Miller, Brad (Inventor)

    2013-01-01

    A radar information processing system is operable to process high bandwidth radar information received from a radar system into low bandwidth radar information that may be communicated to a low bandwidth connection coupled to an electronic flight bag (EFB). An exemplary embodiment receives radar information from a radar system, the radar information communicated from the radar system at a first bandwidth; processes the received radar information into processed radar information, the processed radar information configured for communication over a connection operable at a second bandwidth, the second bandwidth lower than the first bandwidth; and communicates the radar information from a radar system, the radar information communicated from the radar system at a first bandwidth.

  10. A data predistortion technique with memory for QAM radio systems

    Science.gov (United States)

    Karam, Georges; Sari, Hikmet

    1991-02-01

    The authors present an efficient data predistortion technique with memory for compensation of high-power amplifier (HPA) nonlinearities in digital microwave radio systems employing quadrature amplitude modulation (QAM) signal formats. A practical implementation method is described which trades off performance against complexity and which makes it possible to implement this kind of predistorter in 256-QAM and higher-level QAM systems. Using the 16-, 64-, and 256-QAM signal constellations, it is shown that the proposed technique achieves a considerably higher performance than that of conventional memoryless data predistortion or of the predistortion technique with memory based on finite-order inverses of nonlinear systems. Specifically, numerical results show that the proposed technique achieves a gain that is in excess of 2 dB over conventional memoryless data predistortion.

  11. Implementation of an Optimised Cassegrain System for Radio Telescopes

    CERN Document Server

    Holler, C M; Jones, M E; Grainge, K; Kaneko, T

    2007-01-01

    We present the antenna design for a radio interferometer, the Arcminute Microkelvin Imager, together with its beam pattern measurement. Our aim was to develop a low-cost system with high aperture efficiency and low ground-spill across the frequency range 12-18GHz. We use a modified cassegrain system consisting of a commercially-available paraboloidal primary mirror with a diameter of 3.7m, and a shaped secondary mirror. The secondary mirror is oversized with respect to a ray-optics design and has a surface that is bent towards the primary near its outer edge using a square term for the shaping. The antennas are simple to manufacture and therefore their cost is low. The design increased the antenna gain by approximately 10 per cent compared to a normal Cassegrain system while still maintaining low contamination from ground-spill and using a simple design for the horn.

  12. Communications Technology Assessment for the Unmanned Aircraft System (UAS) Control and Non-Payload Communications (CNPC) Link

    Science.gov (United States)

    Bretmersky, Steven C.; Bishop, William D.; Dailey, Justin E.; Chevalier, Christine T.

    2014-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is performing communications systems research for the Unmanned Aircraft System (UAS) in the National Airspace System (NAS) Project. One of the goals of the communications element is to select and test a communications technology for the UAS Control and Non-Payload Communications (CNPC) link. The GRC UAS Modeling and Simulation (M/S) Sub Team will evaluate the performance of several potential technologies for the CNPC link through detailed software simulations. In parallel, an industry partner will implement a technology in hardware to be used for flight testing. The task necessitated a technical assessment of existing Radio Frequency (RF) communications technologies to identify the best candidate systems for use as the UAS CNPC link. The assessment provides a basis for selecting the technologies for the M/S effort and the hardware radio design. The process developed for the technical assessments for the Future Communications Study1 (FCS) was used as an initial starting point for this assessment. The FCS is a joint Federal Aviation Administration (FAA) and Eurocontrol study on technologies for use as a future aeronautical communications link. The FCS technology assessment process methodology can be applied to the UAS CNPC link; however the findings of the FCS are not directly applicable because of different requirements between a CNPC link and a general aeronautical data link. Additional technologies were added to the potential technologies list from the State of the Art Unmanned Aircraft System Communication Assessment developed by NASA GRC2. This document investigates the state of the art of communications as related to UAS. A portion of the document examines potential communications systems for a UAS communication architecture. Like the FCS, the state of the art assessment surveyed existing communications technologies. It did not, however, perform a detailed assessment of the

  13. Development and Testing of a Two-UAV Communication Relay System.

    Science.gov (United States)

    Li, Boyang; Jiang, Yifan; Sun, Jingxuan; Cai, Lingfeng; Wen, Chih-Yung

    2016-10-13

    In the development of beyond-line-of-sight (BLOS) Unmanned Aerial Vehicle (UAV) systems, communication between the UAVs and the ground control station (GCS) is of critical importance. The commonly used economical wireless modules are restricted by the short communication range and are easily blocked by obstacles. The use of a communication relay system provides a practical way to solve these problems, improving the performance of UAV communication in BLOS and cross-obstacle operations. In this study, a communication relay system, in which a quadrotor was used to relay radio communication for another quadrotor was developed and tested. First, the UAVs used as the airborne platform were constructed, and the hardware for the communication relay system was selected and built up. Second, a set of software programs and protocol for autonomous mission control, communication relay control, and ground control were developed. Finally, the system was fully integrated into the airborne platform and tested both indoor and in-flight. The Received Signal Strength Indication (RSSI) and noise value in two typical application scenarios were recorded. The test results demonstrated the ability of this system to extend the communication range and build communication over obstacles. This system also shows the feasibility to coordinate multiple UAVs' communication with the same relay structure.

  14. Development and Testing of a Two-UAV Communication Relay System

    Directory of Open Access Journals (Sweden)

    Boyang Li

    2016-10-01

    Full Text Available In the development of beyond-line-of-sight (BLOS Unmanned Aerial Vehicle (UAV systems, communication between the UAVs and the ground control station (GCS is of critical importance. The commonly used economical wireless modules are restricted by the short communication range and are easily blocked by obstacles. The use of a communication relay system provides a practical way to solve these problems, improving the performance of UAV communication in BLOS and cross-obstacle operations. In this study, a communication relay system, in which a quadrotor was used to relay radio communication for another quadrotor was developed and tested. First, the UAVs used as the airborne platform were constructed, and the hardware for the communication relay system was selected and built up. Second, a set of software programs and protocol for autonomous mission control, communication relay control, and ground control were developed. Finally, the system was fully integrated into the airborne platform and tested both indoor and in-flight. The Received Signal Strength Indication (RSSI and noise value in two typical application scenarios were recorded. The test results demonstrated the ability of this system to extend the communication range and build communication over obstacles. This system also shows the feasibility to coordinate multiple UAVs’ communication with the same relay structure.

  15. Synchronization Techniques for Chaotic Communication Systems

    CERN Document Server

    Jovic, Branislav

    2011-01-01

    Since the early 1990s, when synchronization of chaotic communication systems became a popular research subject, a vast number of scientific papers have been published. However, most of today's books on chaotic communication systems deal exclusively with the systems where perfect synchronization is assumed, an assumption which separates theoretical from practical, real world, systems. This book is the first of its kind dealing exclusively with the synchronization techniques for chaotic communication systems. It describes a number of novel robust synchronization techniques, which there is a lack

  16. COMMUNICATION AND INFORMATION SYSTEM MANAGEMENT INTERNATIONAL

    Directory of Open Access Journals (Sweden)

    Mircea Alexandru Răduţeanu

    2012-01-01

    Full Text Available In recent decades international management itself as a separate component of the general science of leadership, is an intercultural management. In this context of globalization, computerization, any business that wants have a modern management should have a structured information system based on communication, overall objective consisting in providing accurate data in real time all parties, increasing the level of communication. Given these considerations, we conducted this work trying to highlight the role of communication in achieving a modern, emphasizing international management features.The paper is divided into 6 parts, prefaced by an introduction of the paper we presented and completed within a set of conclusions on the effectiveness of communication. During the other paragraphs, we present the theoretical concepts of international management, communication, after which I stressed the role of information communication, managerial communication and will then focus on the process, taking stock of its specific stages in international management.

  17. Communication for command and control systems

    CERN Document Server

    Morris, D J

    1983-01-01

    Communication for Command and Control Systems provides a thorough exposition of the basic theoretical and practical features involved in the design of communication networks for command and control systems. This book focuses primarily on the practical side of computer-controlled communication. This text concentrates on the communication sides of the subject by surveying the means of transferring data between the various processing points and by appraising their potential advantages and possible defects in implementation. In this respect, this book should prove useful for the practicing enginee

  18. Economics of satellite communications systems

    Science.gov (United States)

    Pritchard, Wilbur L.

    This paper is partly a tutorial, telling systematically how one goes about calculating the total annual costs of a satellite communications system, and partly the expression of some original ideas on the choice of parameters so as to minimize these costs. The calculation of costs can be divided into two broad categories. The first is technical and is concerned with estimating what particular equipment will cost and what will be the annual expense to maintain and operate it. One starts in the estimation of any new system by listing the principal items of equipment, such as satellites, earth stations of various sizes and functions, telemetry and tracking equipment and terrestrial interfaces, and then estimating how much each item will cost. Methods are presented for generating such estimates, based on a knowledge of the gross parameters, such as antenna size, coverage area, transmitter power and information rate. These parameters determine the system performance and it is usually possible, knowing them, to estimate the costs of the equipment rather well. Some formulae based on regression analyses are presented. Methods are then given for estimating closely related expenses, such as maintenance and operation, and then an approximate method is developed for estimating terrestrial interconnection costs. It is pointed out that in specific cases when tariff and geographical information are available, it is usually better to work with specific data, but nonetheless it is often desirable, especially in global system estimating, to approximate these interconnect costs without recourse to individual tariffs. The procedure results in a set of costs for the purchase of equipment and its maintenance, and a schedule of payments. Some payments will be incurred during the manufacture of the satellite and before any systems operation, but many will not be incurred until the system is no longer in use, e.g. incentives. In any case, with the methods presented in the first section, one

  19. Smart Radio Spectrum Management for Cognitive Radio

    Directory of Open Access Journals (Sweden)

    Partha Pratim Bhattacharya

    2011-08-01

    Full Text Available Today’s wireless networks are characterized by fixed spectrum assignment policy. The limited availablespectrum and the inefficiency in the spectrum usage necessitate a new communication paradigm toexploit the existing wireless spectrum opportunistically. Cognitive radio is a paradigm for wirelesscommunication in which either a network or a wireless node changes its transmission or receptionparameters to communicate efficiently avoiding interference with licensed or unlicensed users. It cancapture best available spectrum to meet user communication requirements (spectrum management. Inthis work, a fuzzy logic based system for spectrum management is proposed where the radio can shareunused spectrum depending on parameters like distance, signal strength, node velocity and availabilityof unused spectrum. The system is simulated and is found to give satisfactory results.

  20. Outage performance of cognitive radio systems with Improper Gaussian signaling

    KAUST Repository

    Amin, Osama

    2015-06-14

    Improper Gaussian signaling has proved its ability to improve the achievable rate of the systems that suffer from interference compared with proper Gaussian signaling. In this paper, we first study impact of improper Gaussian signaling on the performance of the cognitive radio system by analyzing the outage probability of both the primary user (PU) and the secondary user (SU). We derive exact expression of the SU outage probability and upper and lower bounds for the PU outage probability. Then, we design the SU signal by adjusting its transmitted power and the circularity coefficient to minimize the SU outage probability while maintaining a certain PU quality-of-service. Finally, we evaluate the proposed bounds and adaptive algorithms by numerical results.

  1. Experimental millimeter-wave satellite communications system

    Science.gov (United States)

    Suzuki, Yoshiaki; Shimada, Masaaki; Arimoto, Yoshinori; Shiomi, Tadashi; Kitazume, Susumu

    This paper describes an experimental system of millimeter-wave satellite communications via Japan's Engineering Test Satellite-VI (ETS-VI) and a plan of experiments. Two experimental missions are planned using ETS-VI millimeter-wave (43/38 GHz bands) transponder, considering the millimeter-wave characteristics such as large transmission capacity and possibility to construct a small earth station with a high gain antenna. They are a personal communication system and an inter-satellite communication system. Experimental system including the configuration and the fundamental functions of the onboard transponder and the outline of the experiments are presented.

  2. Space Telecommunications Radio Systems (STRS) Hardware Architecture Standard: Release 1.0 Hardware Section

    Science.gov (United States)

    Reinhart, Richard C.; Kacpura, Thomas J.; Smith, Carl R.; Liebetreu, John; Hill, Gary; Mortensen, Dale J.; Andro, Monty; Scardelletti, Maximilian C.; Farrington, Allen

    2008-01-01

    This report defines a hardware architecture approach for software-defined radios to enable commonality among NASA space missions. The architecture accommodates a range of reconfigurable processing technologies including general-purpose processors, digital signal processors, field programmable gate arrays, and application-specific integrated circuits (ASICs) in addition to flexible and tunable radiofrequency front ends to satisfy varying mission requirements. The hardware architecture consists of modules, radio functions, and interfaces. The modules are a logical division of common radio functions that compose a typical communication radio. This report describes the architecture details, the module definitions, the typical functions on each module, and the module interfaces. Tradeoffs between component-based, custom architecture and a functional-based, open architecture are described. The architecture does not specify a physical implementation internally on each module, nor does the architecture mandate the standards or ratings of the hardware used to construct the radios.

  3. Exploring Systems Engineering (and the Universe) Through the RadioJOVE telescope

    Science.gov (United States)

    Aditi Raj, Anya

    2017-01-01

    Amateur projects in radio astronomy are popular methods to engage in what often seems to be an inaccessible field, and pre-made kits are becoming increasingly available to hobbyists and educators. One such kit is the RadioJOVE, which is attractive due to its simplicity, accessibility and its extensive support network and community of users. When coupled with an education in project management, building the RadioJOVE provides a perfect framework to learn about best practices in completing a project. We will primarily discuss the use of the RadioJOVE project to enhance study in project management and systems engineering. We also intend to discuss the importance of amateur projects such as the RadioJOVE in gaining a holistic understanding of radio astronomy and the project’s potential to spark interest in radio astronomy in students of various disciplines.

  4. DARPA NetCentric radio demonstration

    Science.gov (United States)

    Stotts, Larry B.; Seidel, Scott; Krout, Tim; Kolodzy, Paul

    2007-04-01

    The objective of the DARPA Network Centric Radio System1 (NCRS) Program was to design, develop, integrate, and demonstrate the enabling communication technologies and system capabilities required to enable network centric warfare. NCRS is a First Generation Mobile, Ad Hoc Network (MANET) designed to enable ground and airborne vehicle based on-the-move and on-the-halt network centric connectivity. It demonstrated a gateway architecture that offers interoperability among various current, future, coalition and first responder communications radios, via the network, not the radio. This capability illustrated a new dimension for military communications interoperability.

  5. How to Bootstrap a Human Communication System

    Science.gov (United States)

    Fay, Nicolas; Arbib, Michael; Garrod, Simon

    2013-01-01

    How might a human communication system be bootstrapped in the absence of conventional language? We argue that motivated signs play an important role (i.e., signs that are linked to meaning by structural resemblance or by natural association). An experimental study is then reported in which participants try to communicate a range of pre-specified…

  6. In Search of a System For Communication.

    Science.gov (United States)

    Remirez, Richard J. F.

    A research project sponsored by Wofford College was launched in the summer of 1974 in Spartanburg, South Carolina, to develop a system of communication by which hospital personnel working in an emergency room could communicate with patients who speak a language other than English. The project followed a year-long research effort of previous work…

  7. Nonoral Communication System Project: 1964-1973.

    Science.gov (United States)

    Vicker, Beverly A., Ed.

    Five papers comprising the monograph describe a nonoral communication program which evolved from the clinical experiences of speech pathologists and physical therapists with severely dysarthric, physically handicapped children in a hospital school. Explicated are such aspects of nonoral communication as oral speech dysfunction systems of nonoral…

  8. Simulating Rain Fade In A Communication System

    Science.gov (United States)

    Shalkhauser, Kurt A.; Nagy, Lawrence A.; Svoboda, James K.

    1994-01-01

    Automated, computer-controlled assembly of electronic equipment developed for use in simulation testing of downlink portion of Earth/satellite microwave digital communication system. Designed to show effects upon performance of system of rain-induced fading in received signal and increases in transmitted power meant to compensate for rain-induced fading. Design of communication system improved iteratively in response to results of simulations, leading eventually to design ensuring clear, uninterrupted transmission of digital signals.

  9. Performance Evaluation and Comparative Analysis of SubCarrier Modulation Wake-up Radio Systems for Energy-Efficient Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Joaquim Oller

    2013-12-01

    Full Text Available Energy-efficient communication is one of the main concerns of wireless sensor networks nowadays. A commonly employed approach for achieving energy efficiency has been the use of duty-cycled operation of the radio, where the node’s transceiver is turned off and on regularly, listening to the radio channel for possible incoming communication during its on-state. Nonetheless, such a paradigm performs poorly for scenarios of low or bursty traffic because of unnecessary activations of the radio transceiver. As an alternative technology, Wake-up Radio (WuR systems present a promising energy-efficient network operation, where target devices are only activated in an on-demand fashion by means of a special radio signal and a WuR receiver. In this paper, we analyze a novel wake-up radio approach that integrates both data communication and wake-up functionalities into one platform, providing a reconfigurable radio operation. Through physical experiments, we characterize the delay, current consumption and overall operational range performance of this approach under different transmit power levels. We also present an actual single-hop WuR application scenario, as well as demonstrate the first true multi-hop capabilities of a WuR platform and simulate its performance in a multi-hop scenario. Finally, by thorough qualitative comparisons to the most relevant WuR proposals in the literature, we state that the proposed WuR system stands out as a strong candidate for any application requiring energy-efficient wireless sensor node communications.

  10. Performance evaluation and comparative analysis of SubCarrier Modulation Wake-up Radio systems for energy-efficient wireless sensor networks.

    Science.gov (United States)

    Oller, Joaquim; Demirkol, Ilker; Casademont, Jordi; Paradells, Josep; Gamm, Gerd Ulrich; Reindl, Leonhard

    2013-12-19

    Energy-efficient communication is one of the main concerns of wireless sensor networks nowadays. A commonly employed approach for achieving energy efficiency has been the use of duty-cycled operation of the radio, where the node's transceiver is turned off and on regularly, listening to the radio channel for possible incoming communication during its on-state. Nonetheless, such a paradigm performs poorly for scenarios of low or bursty traffic because of unnecessary activations of the radio transceiver. As an alternative technology, Wake-up Radio (WuR) systems present a promising energy-efficient network operation, where target devices are only activated in an on-demand fashion by means of a special radio signal and a WuR receiver. In this paper, we analyze a novel wake-up radio approach that integrates both data communication and wake-up functionalities into one platform, providing a reconfigurable radio operation. Through physical experiments, we characterize the delay, current consumption and overall operational range performance of this approach under different transmit power levels. We also present an actual single-hop WuR application scenario, as well as demonstrate the first true multi-hop capabilities of a WuR platform and simulate its performance in a multi-hop scenario. Finally, by thorough qualitative comparisons to the most relevant WuR proposals in the literature, we state that the proposed WuR system stands out as a strong candidate for any application requiring energy-efficient wireless sensor node communications.

  11. Analog and digital communication systems

    CERN Document Server

    Roden, Martin S

    1996-01-01

    New edition of an introductory text that balances theoretical foundations with practical design. Reorganization and updates in this edition include the section on digital communications as well as design applications and computer exercises: many graphs are prepared and formulas solved using MATLAB...

  12. Communication architectures for systems-on-chip

    CERN Document Server

    Ayala, Jose L

    2011-01-01

    A presentation of state-of-the-art approaches from an industrial applications perspective, Communication Architectures for Systems-on-Chip shows professionals, researchers, and students how to attack the problem of data communication in the manufacture of SoC architectures. With its lucid illustration of current trends and research improving the performance, quality, and reliability of transactions, this is an essential reference for anyone dealing with communication mechanisms for embedded systems, systems-on-chip, and multiprocessor architectures--or trying to overcome existing limitations.

  13. MF-CRA: Multi-Function Cognitive Radio Architecture for Space Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — EpiSys Science, Inc. and University of Arizona propose to develop, implement, and demonstrate Multi-Function Cognitive Radio Architecture (MF-CRA) for Space...

  14. 47 CFR 13.211 - Commercial radio operator license examination.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Commercial radio operator license examination. 13.211 Section 13.211 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL RADIO OPERATORS Examination System § 13.211 Commercial radio operator license examination. (a) Each session...

  15. Ultra Low Power, Radiation Tolerant UHF Radio Technologies for In Situ Communication Applications

    Science.gov (United States)

    Lay, N. E.

    2001-01-01

    For future deep space missions, significant reductions in the mass and power requirements for short-range telecommunication systems will be critical in enabling a wide variety of new mission concepts. These possibilities include penetrators, gliders, miniature rovers, and sensor networks. Under joint funding from NASA's Cross Enterprise and JPL's Telecommunications and Mission technology programs, recent development activity has focused on the design of ultralow mass and power transceiver systems and subsystems suitable for operation in a flight environment. For these efforts, the functionality of the transceiver has been targeted towards a specific Mars communications scenario. However, the overall architecture is well suited to any short or medium range application where a remote probe will aperiodically communicate with a base station, possibly an orbiter, for the eventual purpose of relaying science information back to Earth. In 2001, these sponsors have been augmented with collaborative expertise and funding from JPL's Center for Integrated Space Microsystems in order to migrate existing concepts and designs to a System on a Chip (SOAC) solution. Additional information is contained in the original extended abstract.

  16. Ultra Low Power, Radiation Tolerant UHF Radio Technologies for In Situ Communication Applications

    Science.gov (United States)

    Lay, N. E.

    2001-01-01

    For future deep space missions, significant reductions in the mass and power requirements for short-range telecommunication systems will be critical in enabling a wide variety of new mission concepts. These possibilities include penetrators, gliders, miniature rovers, and sensor networks. Under joint funding from NASA's Cross Enterprise and JPL's Telecommunications and Mission technology programs, recent development activity has focused on the design of ultralow mass and power transceiver systems and subsystems suitable for operation in a flight environment. For these efforts, the functionality of the transceiver has been targeted towards a specific Mars communications scenario. However, the overall architecture is well suited to any short or medium range application where a remote probe will aperiodically communicate with a base station, possibly an orbiter, for the eventual purpose of relaying science information back to Earth. In 2001, these sponsors have been augmented with collaborative expertise and funding from JPL's Center for Integrated Space Microsystems in order to migrate existing concepts and designs to a System on a Chip (SOAC) solution. Additional information is contained in the original extended abstract.

  17. The Deep Space Network: A Radio Communications Instrument for Deep Space Exploration

    Science.gov (United States)

    Renzetti, N. A.; Stelzried, C. T.; Noreen, G. K.; Slobin, S. D.; Petty, S. M.; Trowbridge, D. L.; Donnelly, H.; Kinman, P. W.; Armstrong, J. W.; Burow, N. A.

    1983-01-01

    The primary purpose of the Deep Space Network (DSN) is to serve as a communications instrument for deep space exploration, providing communications between the spacecraft and the ground facilities. The uplink communications channel provides instructions or commands to the spacecraft. The downlink communications channel provides command verification and spacecraft engineering and science instrument payload data.

  18. BER performance analysis of OFDM-MIMO system using GNU Radio

    Directory of Open Access Journals (Sweden)

    Singh M.Ushamahesh

    2016-01-01

    Full Text Available Multiple Input Multiple Output (MIMO channels can be used to increase the data rate and the channel capacity by employing multiple transmitting and receiving antennas at both the ends of a wireless communication system. MIMO systems employ Orthogonal Frequency Division Multiplexing (OFDM technique and it uses separate antennas at both the transmitter and receiver to increase the data rate and with OFDM, instead of a single carrier, the main information is modulated into a number of independent sub-carrier signals which are orthogonal to each other. This paper presents an OFDM-MIMO transceiver design and the performance analysis of the system based on Error rate for different modulation techniques using GNU Radio. OFDM is chosen over a single carrier solution due to lower complexity of equalizers for high delay spread channels or high data rates. So the combination of MIMO-OFDM system has become a potential technology for high speed data transmission and efficient utilization of the channel spectrum for the modern wireless communication networks.

  19. Multiagent -Learning for Aloha-Like Spectrum Access in Cognitive Radio Systems

    Directory of Open Access Journals (Sweden)

    Li Husheng

    2010-01-01

    Full Text Available An Aloha-like spectrum access scheme without negotiation is considered for multiuser and multichannel cognitive radio systems. To avoid collisions incurred by the lack of coordination, each secondary user learns how to select channels according to its experience. Multiagent reinforcement leaning (MARL is applied for the secondary users to learn good strategies of channel selection. Specifically, the framework of -learning is extended from single user case to multiagent case by considering other secondary users as a part of the environment. The dynamics of the -learning are illustrated using a Metrick-Polak plot, which shows the traces of -values in the two-user case. For both complete and partial observation cases, rigorous proofs of the convergence of multiagent -learning without communications, under certain conditions, are provided using the Robins-Monro algorithm and contraction mapping, respectively. The learning performance (speed and gain in utility is evaluated by numerical simulations.

  20. Fly by wireless: Evaluation of the Zigbee radio system for in vehicle connectivity

    OpenAIRE

    Dawson, J.F.; Hope, D C; Panitz, M; Christopoulos, C

    2008-01-01

    This paper describes the unique propagation environment, in vehicles structures, and gives an overview of commercial off-the-shelf (COTS) radio systems which might be considered for use in wireless networks within vehicles. Some initial results describing the performance of the Zigbee radio system in a reverberant environment are then presented.

  1. Broadcast Communication by System Frequency Modulation

    DEFF Research Database (Denmark)

    Douglass, Philip James; You, Shi; Heussen, Kai

    2012-01-01

    off-nominal system frequency values is a novel narrowband broadcast communications channel between system operators and frequency sensitive distributed energy resources (FS-DER). The feasibility of the proposed system is evaluated on an existing island power system in Denmark. This study shows...

  2. Communication system at Dakshin Gangotri, Antarctica

    Digital Repository Service at National Institute of Oceanography (India)

    Sudhakar, T.

    A reliable communication system is a major requirement for a remote station like 'Dakshin Gangotri' where traditional equipments cannot function effectively due to long distances and peculiar weather and ionospheric conditions. The satellite...

  3. Extreme Environment High Temperature Communication Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this project is to develop and demonstrate a communications system capable of operation at extreme temperatures and pressures in hostile and corrosive...

  4. Protection of Communication System From Solar Flares

    OpenAIRE

    Karthik, K.(Department of Physics, New York University, New York, NY, United States of America); Shirvram, B.

    2008-01-01

    Solar flares are enormous explosions on the surface of the sun and they release energy of the order of billion megatons of TNThis energy is in the form of electromagnetic radiations such as alpha, gamma, and ultraviolet rays. When exposed to high doses of radiation like 2-15 kilorad (Si), silicon integrated circuits in satellite communication systems fail to operate properly, thus affecting the performance of communication systems. Therefore, the major issue that needs to be addressed is the ...

  5. L'arrivée du WiFi, technologie de télécommunication radio

    OpenAIRE

    Dumé, Bel; Ubéda, Stéphane

    2012-01-01

    National audience; La technologie radio 802.11, désormais bien connue sous le nom de Wi-Fi, est développée à la fin des années 1990, mais sa mise en oeuvre est assez compliquée et il faudra attendre les années 2002-2003 pour que les vraies cartes Wi-Fi arrivent sur le marché et ouvrent le champ des applications d'objets mobiles communicants.

  6. Optoelectronic Oscillators for Communication Systems

    Science.gov (United States)

    Romeira, Bruno; Figueiredo, José

    We introduce and report recent developments on a novel five port optoelectronic voltage controlled oscillator consisting of a resonant tunneling diode (RTD) optical-waveguide integrated with a laser diode. The RTD-based optoelectronic oscillator (OEO) has both optical and electrical input and output ports, with the fifth port allowing voltage control. The RTD-OEO locks to reference radio-frequency (RF) sources by either optical or electrical injection locking techniques allowing remote synchronization, eliminating the need of impedance matching between traditional RF oscillators. RTD-OEO functions include generation, amplification and distribution of RF carriers, clock recovery, carrier recovery, modulation and demodulation and frequency synthesis. Self-injection locking operation modes, where small portions of the output electrical/optical signals are fed back into the electrical/optical input ports, are also proposed. The self-phase locked loop configuration can give rise to low-noise high-stable oscillations, not limited by the RF source performance and with no need of external optoelectronic conversion.

  7. AGENT AND RADIO FREQUENCY IDENTIFICATION BASED ARCHITECTURE FOR SUPERMARKET INFORMATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Hasan Al-Sakran

    2013-01-01

    Full Text Available In recent years the acceptance of Radio Frequency Identification (RFID technology in business environments has been increasing rapidly due to its competitive business value. Adopting a suitable RFID-based information system has become increasingly important for supermarkets. However, most supermarkets still use conventional barcode-based systems to manage their information processes, which are consistently reported as one of the most unenthusiastic aspects of supermarket shopping for both customers and management. We propose an RFID agent-based architecture that adopts intelligent agent technology with an RFID based applications. RFID provides capability to uniquely identify an object within a supermarket area, while agents are able to establish a channel of communication which can be used to facilitate communications between a RFID device and supermarket back-end system. The proposed framework includes a design of intelligent mobile shopping cart equipped with both RFID and agent technologies. As a result of using the proposed RFID agent based architecture, the customer shopping experience will be improved due to ease of retrieving of the detailed information on items and quick checkout by scanning all items at once, thus eliminating queues. From supermarket management point of view the proposed architecture will reduce the cost of operation e.g., decreasing cost of goods sold which comes in the form of labor efficiency in areas of checkout operation, inventory management and alerting the supermarket management when a certain product is running out of stock and needs to be restocked.

  8. Low Frequency Radio-wave System for subsurface investigation

    Science.gov (United States)

    Soldovieri, Francesco; Gennarelli, Gianluca; Kudelya, Anatoliy; Denisov, Alexander

    2015-04-01

    Low frequency radio-wave methods (RWM) allow subsurface investigations in terms of lithological structure characterization, detection of filtration flows of ground water, anthropogenic and natural cavities. In this contribution, we present a RWM that exploits two coils working at frequencies of few MHz as transmitting and receiving antennas. The basic principle of this inductive method is as follows. The primary alternating electromagnetic field radiated by the transmitting coil induces eddy currents in the subsurface mainly due to the conductivity anomalies. These eddy currents generate a secondary (scattered) magnetic field which overlaps to the incident magnetic field and is detected by the receiving coil. Despite the simple operation of the system, the complexity of the electromagnetic scattering phenomenon at hand must be properly modeled to achieve adequate performance. Therefore, an advanced data processing technique, belonging to the class of the inverse scattering approaches, has been developed by the authors in a full 3D geometry. The proposed method allows to deal with data collected on a scanning surface under a dipole inductive profiling (DIP) modality, where the transmitting/receiving coils are moved simultaneously with fixed offset (multi-bistatic configuration). The hardware, called Dipole Inductive Radio-wave System (DIRS), is composed by an electronic unit and transmitting and receiving loop antennas radiating at frequencies of few MHz (2-4 MHz), which are installed on theodolite supports. The compactness of DIRS and its robustness to external electromagnetic interference offers the possibility to perform geophysical research up to the depth of some tens of meters and under several types of ground and water surfaces, vegetation, and weather conditions. The light weight and small size of system (the single antenna with support weights about 5 kg and has a diameter of 0.5m) allows two operators to perform geophysical research without disturbing the

  9. Sex-specific responses to territorial intrusions in a communication network: Evidence from radio-tagged great tits.

    Science.gov (United States)

    Snijders, Lysanne; van Oers, Kees; Naguib, Marc

    2017-02-01

    Signals play a key role in the ecology and evolution of animal populations, influencing processes such as sexual selection and conflict resolution. In many species, sexually selected signals have a dual function: attracting mates and repelling rivals. Yet, to what extent males and females under natural conditions differentially respond to such signals remains poorly understood, due to a lack of field studies that simultaneously track both sexes. Using a novel spatial tracking system, we tested whether or not the spatial behavior of male and female great tits (Parus major) changes in relation to the vocal response of a territorial male neighbor to an intruder. We tracked the spatial behavior of male and female great tits (N = 44), 1 hr before and 1 hr after simulating territory intrusions, employing automatized Encounternet radio-tracking technology. We recorded the spatial and vocal response of the challenged males and quantified attraction and repulsion of neighboring males and females to the intrusion site. We additionally quantified the direct proximity network of the challenged male. The strength of a male's vocal response to an intruder induced sex-dependent movements in the neighborhood, via female attraction and male repulsion. Stronger vocal responders were older and in better body condition. The proximity networks of the male vocal responders, including the number of sex-dependent connections and average time spent with connections, however, did not change directly following the intrusion. The effects on neighbor movements suggest that the strength of a male's vocal response can provide relevant social information to both the males and the females in the neighborhood, resulting in both sexes adjusting their spatial behavior in contrasting ways, while the social proximity network remained stable. This study underlines the importance of "silent" eavesdroppers within communication networks for studying the dual functioning and evolution of sexually

  10. Analytical Frameworks of Cooperative and Cognitive Radio Systems with Practical Considerations

    KAUST Repository

    Khan, Fahd Ahmed

    2013-08-01

    Cooperative and cognitive radio systems have been proposed as a solution to improve the quality-of-service (QoS) and spectrum efficiency of existing communication systems. The objective of this dissertation is to propose and analyze schemes for cooperative and cognitive radio systems considering real world scenarios and to make these technologies implementable. In most of the research on cooperative relaying, it has been assumed that the communicating nodes have perfect channel state information (CSI). However, in reality, this is not the case and the nodes may only have an estimate of the CSI or partial knowledge of the CSI. Thus, in this dissertation, depending on the amount of CSI available, novel receivers are proposed to improve the performance of amplify-and forward relaying. Specifically, new coherent receivers are derived which do not perform channel estimation at the destination by using the received pilot signals directly for decoding. The derived receivers are based on new metrics that use distribution of the channels and the noise to achieve improved symbol-error-rate (SER) performance. The SER performance of the derived receivers is further improved by utilizing the decision history in the receivers. In cases where receivers with low complexity are desired, novel non-coherent receiver which detects the signal without knowledge of CSI is proposed. In addition, new receivers are proposed for the situation when only partial CSI is available at the destination i.e. channel knowledge of either the source-relay link or the relay-destination link but not both, is available. These receivers are termed as `half-coherent receivers\\' since they have channel-state-information of only one of the two links in the system. In practical systems, the CSI at the communicating terminals becomes outdated due to the time varying nature of the channel and results in system performance degradation. In this dissertation, the impact of using outdated CSI for relay selection on

  11. Joint Tactical Radio System Handheld, Manpack, and Small Form Fit Radios (JTRS HMS)

    Science.gov (United States)

    2013-12-01

    Dev Est - Development Estimate DoD - Department of Defense DSN - Defense Switched Network Econ - Economic Eng - Engineering Est - Estimating FMS...2004 Milestone C Decision: HMS MAY 2011 MAY 2011 MAY 2011 MAY 2011 IOT &E: AN/PRC-154 Rifleman Radio NOV 2011 NOV 2011 MAY 2012 NOV 2011 MOT&E: AN/PRC-155...Test and Evaluation FRP - Full Rate Production IOT &E - Initial Operational Test and Evaluation IPR - In-Process Review MOT&E - Multi-Service

  12. Spatial Modulation for MIMO Communication Systems

    Directory of Open Access Journals (Sweden)

    Reginaldo Nunes

    2012-11-01

    Full Text Available This work provides a review on the main spatial modulation (SM schemes, suitable to wireless communication systems. Performance, complexity and diversity gain of the three new spatial SM schemes suitable for multiple-input-multiple-output (MIMO communication systems are analyzed: a transmission scheme for spatial modulation (SM scheme; b space shift keying (SSK scheme; c generalized space shift keying (GSSK scheme. These three schemes offer low complexity, higher data rate when compared to single-input-single-output (SISO communication systems, as well as design flexibility, while exploits randomness characteristics of wireless communication channel for data transmission. The paper aims to explore the main features of those three SM schemes and to evaluate the inherent performance-complexity trade-off in order to determine which of those schemes results in a higher energy and spectral efficiencies.

  13. Converging Information and Communication Systems

    DEFF Research Database (Denmark)

    Øst, Alexander

    2003-01-01

    This Ph.D.-project investigates the process of convergence between television and computers. Identifying three “promises of convergence”: interoperability, quality and interactivity, the project examines the key properties of the computer and television sectors, which have had - or are expected...... in the future to have - significant importance to the process and consequences of the convergence. The project focuses on the appliances, i.e. the TV sets, the computers and their peripheral equipment. It also takes into account the infrastructure and signals, which contain and deliver the information...... and communication, as well as the nature of the content and the usage scenarios of consumers....

  14. The digital sport radio.

    Directory of Open Access Journals (Sweden)

    Hilario José ROMERO BEJARANO

    2014-07-01

    Full Text Available Radio has been immersed in recent years in a phase of technological integration and business of multimedia, as well as diversification of systems and channels for broadcasting. In addition, Internet has been consolidated as the platform of digital radio that more has evolved as a result of its continued expansion. However, the merger radio-Internet must be understood as a new form of communication, and not solely as a new complementary medium. In this context, it is of great interest to analyze that transformations in the way of reception, contents, languages, programs and schedules, has brought with it for the radio that integration. To this end is taken as main reference the sports areas, a key aspect and broadly representative of the current broadcasting landscape.

  15. Simulation of Wireless Digital Communication Systems

    Directory of Open Access Journals (Sweden)

    A. Mohammed

    2004-12-01

    Full Text Available Due to the explosive demands for high speed wireless services, suchas wireless Internet, email and cellular video conferencing, digitalwireless communications has become one of the most exciting researchtopics in electrical and electronic engineering field. The never-endingdemand for such personal and multimedia services, however, demandstechnologies operating at higher data rates and broader bandwidths. Inaddition, the complexity of wireless communication and signalprocessing systems has grown considerably during the past decade.Therefore, powerful computer­aided techniques are required for theprocess of modeling, designing, analyzing and evaluating theperformance of digital wireless communication systems. In this paper wediscuss the basic propagation mechanisms affecting the performance ofwireless communication systems, and present a simple, powerful andefficient way to simulate digital wireless communication systems usingMatlab. The simulated results are compared with the theoreticalanalysis to validate the simulator. The simulator is useful inevaluating the performance of wireless multimedia services and theassociated signal processing structures and algorithms for current andnext generation wireless mobile communication systems.

  16. Cognitive radio networks medium access control for coexistence of wireless systems

    CERN Document Server

    Bian, Kaigui; Gao, Bo

    2014-01-01

    This book gives a comprehensive overview of the medium access control (MAC) principles in cognitive radio networks, with a specific focus on how such MAC principles enable different wireless systems to coexist in the same spectrum band and carry out spectrum sharing.  From algorithm design to the latest developments in the standards and spectrum policy, readers will benefit from leading-edge knowledge of how cognitive radio systems coexist and share spectrum resources.  Coverage includes cognitive radio rendezvous, spectrum sharing, channel allocation, coexistence in TV white space, and coexistence of heterogeneous wireless systems.   • Provides a comprehensive reference on medium access control (MAC)-related problems in the design of cognitive radio systems and networks; • Includes detailed analysis of various coexistence problems related to medium access control in cognitive radio networks; • Reveals novel techniques for addressing the challenges of coexistence protocol design at a higher level ...

  17. Newnes communications technology handbook

    CERN Document Server

    Lewis, Geoff

    1994-01-01

    Newnes Communications Technology Handbook provides a discussion on different topics relevant to communications technology. The book is comprised of 39 chapters that tackle a wide variety of concern in communications technology. The coverage of the text includes technologies, such as analog digital communications systems, radio frequency receiver, and satellite systems. The book also discusses some methods and techniques used in communications technology, including mixer signal processing, modulation and demodulation, and spread spectrum techniques. The text will be of great use to engineers, t

  18. 基于安全性评估的民用客机VHF通信电台架构*%Civil Airliner VHF Communication Radio Architecture Based on Safety Assessment

    Institute of Scientific and Technical Information of China (English)

    郑力; 廖祯林

    2013-01-01

    The airworthiness certification for civil airliner VHF communication radio requires device-level safety assessment . This paper briefly outlines the airborne systems and equipment safety assessment guidelines,meth-ods and process . Then it describes the failure modes for each module to compose a VHF communication radioand modular failure rate,and figures out the failure probability of single-channel architecture VHF communica-tion radio with the fault tree method recommended by SAE ARP 4761 . The estimation result indicates that itdoes not meet the fail probability requirements allocated by aircraft grade PSSA (Preliminary System Safety As-sessment). Finally,the non-similar multi-channel architecture of VHF communication radio is proposed in order to reduce the failure probability of the radio . Analysis shows that VHF communication radio with this implemen-tation architecture can achieve lower failure probability than ordinary single-channel implementation architecture VHF communication radio.%  进行设备级的安全性评估是民用客机VHF通信电台适航审定的要求。简述了机载系统和设备的安全性评估指南、方法及过程,描述了VHF通信电台各组成模块的失效模式及失效率,并运用SAE ARP 4761所推荐的故障树方法估算出了单通道架构VHF通信电台的失效概率,估算结果说明单通道架构VHF通信电台不能满足飞机级PSSA(Preliminary System Safety Assessment)分配的失效概率要求。最后,为了降低VHF通信电台的失效概率,提出了VHF通信电台的非相似多通道实现架构。分析表明,与单通道架构相比,非相似多通道实现架构的VHF通信电台具有更低的失效概率。

  19. Optimal Design of Dual-Hop VLC/RF Communication System With Energy Harvesting

    KAUST Repository

    Rakia, Tamer

    2016-07-28

    In this letter, we consider a dual-hop heterogeneous visible light communication (VLC)/radio frequency (RF) communication system to extend the coverage of VLC systems. Besides detecting the information over VLC link, the relay is able to harvest energy from the first-hop VLC link, by extracting the direct current component of the received optical signal, and uses the harvested energy to retransmit the data to a mobile terminal over the second-hop RF link. We investigate the optimal design of the hybrid system in terms of data rate maximization.

  20. System performance testing of the DVA1 radio telescope

    Science.gov (United States)

    Knee, Lewis B. G.; Baker, Lynn A.; Gray, Andrew D.; Hovey, Gary J.; Kesteven, Michael J.; Lacy, Gordon; Robishaw, Timothy

    2016-07-01

    DVA1 (Dish Verification Antenna 1) is a highly innovative rim-supported single-piece composite-material dish radio telescope developed at the National Research Council Canada (NRC). It has a feed-high offset Gregorian optical design with a primary effective diameter of 15 m. DVA1 has been undergoing mechanical and astronomical system tests since 2014. Astronomical measurements were made in L band using a prototype front end developed for MeerKAT by EMSS Antennas (South Africa), including aperture efficiency, beam profiles, sensitivity, and tipping curves. The clean shaped optics, careful attention to feed design, and high sensitivity of the L band receiver (Trx 6 K) yield a system with high aperture efficiency ( 0.8), excellent sensitivity ( 9 m2/K), and low spillover ( 4 K). Observations of 21 cm atomic hydrogen lines towards standard sources demonstrate the low stray radiation pickup of the antenna. Ku band holography has measured the effective surface accuracy and stability of the dual-reflector antenna. The effective RMS of 0.85 mm implies a Ruze efficiency of 0.88 at 10 GHz and 0.60 at 20 GHz. The surface is stable ( 10% variation in surface RMS) over the limited range of environmental conditions tested. Testing continues for characterization of pointing, low frequency performance (antenna, DVA3, which will have a more accurate surface and be usable at frequencies at least up to Q band (30 - 50 GHz).

  1. Energy-Efficient Power Allocation for Underlay Cognitive Radio Systems

    KAUST Repository

    Sboui, Lokman

    2015-09-01

    We present a power allocation framework for spectrum sharing Cognitive Radio (CR) systems based on maximizing the energy efficiency (EE). First, we show that the relation between the EE and the spectral efficiency (SE) is strictly increasing in contrast with the SE-EE trade-off discussed in the literature. We also solve a non-convex problem and explicitly derive the optimal power for the proposed average EE under either a peak or an average power constraint. We apply our results to the underlay CR systems where the power is limited by an additional interference constraint. When the instantaneous channel is not available, we provide a necessary and sufficient condition for the optimal power and present a simple sub-optimal power. In the numerical results, we show that the proposed EE corresponds to a higher SE at mid-range and high power regime compared to the classical EE. We also show that the sup-optimal solution is very close to the optimal solution. In addition, we deduce that the absence of instantaneous CSI affects the EE and the SE at high power regime compared to full CSI. In the CR context, we show that the interference threshold has a minimal effect on the EE compared to the SE.

  2. OPTIMIZATION OF SPECTRUM UTILIZATION IN COGNITIVE RADIO SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Li Hongjiang; Zhu Qi

    2011-01-01

    In Cognitive Radio (CR) networks,CR user has to detect the spectrum channel periodically to make sure that the channel is idle during data transmission frame in order to avoid the collisions to the primary users.Hence recent research has been focused on the interference avoidance problem.Quality of Service (QoS) requirement of CR user will affect the time of data transmission in each frame.In this paper,in order to solve the interference avoidance and spectrum utilization problems without cooperation among CR users,a new scheme to obtain the optimal duration of data transmission frame is proposed to maximize the spectrum utilization and guarantee the protection to the primary users.The main advantages of our proposed scheme include the followings:(1) QoS requirement of CR user is concerned; (2) p-persistent Media Access Control (MAC) random access is used to avoid the collisions among CR users; (3) CR network system capacity is considered.We develop a Markov chain of the primary spectrum channel states and an exponential distribution of the CR user's traffic model to analyze the performance of our proposed scheme.Computer simulation shows that there is an optimal data transmission time to maximize the spectrum utilization.However,the regulatory constraint of the collision rate to the primary users has to be satisfied at the expense of spectrum utilization.And also the tradeoff between the spectrum utilization and the capacity of the CR system is taken into account.

  3. Radio frequency fields generated by the S-band communication link on OV102

    Science.gov (United States)

    Murphy, G. B.; Shawhan, S. D.

    1984-01-01

    The Space Shuttle STS-3 mission carried a Plasma Diagnostics Package (PDP) whose instrumentation included an S-band antenna and detector. The PDP was maneuvered by the Remote Manipulator System arm through a computer controlled sequence in the Orbiter's X-Z plane, above the quad and hemi S-band communications antennas. Antenna field strength measurements were conducted during transmitter high power modes, and the results were compared to ground full scale measurements and predictions. A field strength 4.8 + or - 3 dB higher than predicted is noted. This RF field is primarily due to the quad PM transmitter, whose power output of 115 W compares with 15 W for the hemi.

  4. Portable Wireless LAN Device and Two-Way Radio Threat Assessment for Aircraft VHF Communication Radio Band

    Science.gov (United States)

    Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Williams, Reuben A.; Smith, Laura J.; Salud, Maria Theresa P.

    2004-01-01

    This document summarizes the safety analysis performed on a Flight Guidance System (FGS) requirements model. In particular, the safety properties desired of the FGS model are identified and the presence of the safety properties in the model is formally verified. Chapter 1 provides an introduction to the entire project, while Chapter 2 gives a brief overview of the problem domain, the nature of accidents, model based development, and the four-variable model. Chapter 3 outlines the approach. Chapter 4 presents the results of the traditional safety analysis techniques and illustrates how the hazardous conditions associated with the system trace into specific safety properties. Chapter 5 presents the results of the formal methods analysis technique model checking that was used to verify the presence of the safety properties in the requirements model. Finally, Chapter 6 summarizes the main conclusions of the study, first and foremost that model checking is a very effective verification technique to use on discrete models with reasonable state spaces. Additional supporting details are provided in the appendices.

  5. Communication and control for networked complex systems

    CERN Document Server

    Peng, Chen; Han, Qing-Long

    2015-01-01

    This book reports on the latest advances in the study of Networked Control Systems (NCSs). It highlights novel research concepts on NCSs; the analysis and synthesis of NCSs with special attention to their networked character; self- and event-triggered communication schemes for conserving limited network resources; and communication and control co-design for improving the efficiency of NCSs. The book will be of interest to university researchers, control and network engineers, and graduate students in the control engineering, communication and network sciences interested in learning the core principles, methods, algorithms and applications of NCSs.

  6. Experimental Investigation of Subject-Specific On-Body Radio Propagation Channels for Body-Centric Wireless Communications

    Directory of Open Access Journals (Sweden)

    Mohammad Monirujjaman Khan

    2014-01-01

    Full Text Available In this paper, subject-specific narrowband (2.45 GHz and ultra-wideband (3–10.6 GHz on-body radio propagation studies in wireless body area networks (WBANs were performed by characterizing the path loss for eight different human subjects of different shapes and sizes. The body shapes and sizes of the test subjects used in this study are characterised as thin, medium build, fatty, shorter, average height and taller. Experimental investigation was made in an indoor environment using a pair of printed monopoles (for the narrowband case and a pair of tapered slot antennas (for the ultra-wideband (UWB case. Results demonstrated that, due to the different sizes, heights and shapes of the test subjects, the path loss exponent value varies up to maximum of 0.85 for the narrowband on-body case, whereas a maximum variation of the path loss exponent value of 1.15 is noticed for the UWB case. In addition, the subject-specific behaviour of the on-body radio propagation channels was compared between narrowband and UWB systems, and it was deduced that the on-body radio channels are subject-specific for both narrowband and UWB system cases, when the same antennas (same characteristics are used. The effect of the human body shape and size variations on the eight different on-body radio channels is also studied for both the narrowband and UWB cases.

  7. A system-level design method for cognitive radio on a reconfigurable multi-processor architecture

    NARCIS (Netherlands)

    Zhang, Qiwei; Kokkeler, A.B.J.; Smit, G.J.M.

    2007-01-01

    The future trend of software defined radio (SDR) platforms moves toward reconfigurable Multiprocessor System-on−Chips (MPSoCs). However, there is a gap between the modelling of the dynamic radio applications and the optimized implementation of the application on reconfigurable multiprocessor archite

  8. Subjective voice quality, communicative ability and swallowing after definitive radio(chemo)therapy, laryngectomy plus radio(chemo)therapy, or organ conservation surgery plus radio(chemo)therapy for laryngeal and hypopharyngeal cancer.

    Science.gov (United States)

    Szuecs, Marcella; Kuhnt, Thomas; Punke, Christoph; Witt, Gabriele; Klautke, Gunther; Kramp, Burkhard; Hildebrandt, Guido

    2015-01-01

    This retrospective analysis focusses on the impact of therapy on perceived long-term post-cancer treatment function. A validated questionnaire including items and components for the assessment of communicative ability, quality of voice and swallowing was sent to 129 patients. All patients were treated between 1998 and 2007. A total of 76 patients (58.9%) with carcinoma of the larynx or hypopharynx replied to the questionnaire. Data was evaluated retrospectively. Therapy delivered was definitive radio(chemo)therapy (defchRT/RT) (21/76, 28%), laryngectomy + radio(chemo)therapy (LE + chRT/RT) (28/76, 37%), or larynx conservation surgery + radio(chemo)therapy (LCS + chRT/RT) (27/76, 36%). Radiotherapy was administered using 2D- or 3D-conformal planning. The most common concomitant chemotherapy delivered was cisplatin + 5FU. For statistical analyses of the components, averages were calculated and tested using the Kruskal-Wallis test and the U-test of Mann and Whitney. Differences were assessed by the Monte Carlo method or Fisher's exact test. The single item rates were compared with Fisher's exact test. Mean follow-up was 56.7 months (range, 8-130 months). After defchRT/RT, patients trended towards more substantial-strong hoarseness compared with LCS + chRT/RT (P = 0.2). After LE, patients were dissatisfied with their artificial larynx/electrolarynx and the tone of their voice (P = 0.3, P = 0.07) and communicative ability (P = 0.005, P = 0.008) compared with those treated with defchRT/RT and LCS + chRT/RT, respectively. Dysphagia and additional percutaneous endoscopic gastrostomy (PEG) feeding were more frequent after defchRT/RT in comparison with the other two groups (P < 0.05). Voice quality and communicative ability were slightly worse after defchRT/RT and LE + chRT/RT, but satisfying with all treatment modalities. Further development of the therapy approach is necessary to reduce long-term side effects, with measures of post-treatment function as important endpoints.

  9. Study of manufacturing resource perception and process control of a radio-frequency-identification-enabled decentralized flexible manufacturing system

    Directory of Open Access Journals (Sweden)

    Zengqiang Jiang

    2017-01-01

    Full Text Available The fusion of mechatronics, communication, control, and information technologies has introduced new automation paradigms into the production environment. Plug-and-play flexible manufacturing systems will become suitable approaches in the future for the development of modular, flexible, and reconfigurable manufacturing systems, addressing the requirements of global markets. This article introduces a Petri Net model-driven methodology for the development, validation, and operation of a radio-frequency identification-enabled decentralized flexible manufacturing system. After analyzing the manufacturing processes and resources of a flexible manufacturing system, the manufacturing resources are classified into active and passive resources. Each active resource is equipped with a radio-frequency identification reader and each passive resource is banded with a radio-frequency identification tag. Real-time state and behavior logic models are built for manufacturing resources based on extended Petri Nets; the models are translated into XML and integrated with the manufacturing resources. In this fashion, each manufacturing resource becomes an autonomous agent, and it can make self-decisions and update its status through the twinned models. In this manner, automatic perception and process control are realized. Finally, the effectiveness and feasibility of the method are verified in an experimental system.

  10. A native IP satellite communications system

    Science.gov (United States)

    Koudelka, O.; Schmidt, M.; Ebert, J.; Schlemmer, H.; Kastner-Puschl, S.; Riedler, W.

    2004-08-01

    ≪ In the framework of ESA's ARTES-5 program the Institute of Applied Systems Technology (Joanneum Research) in cooperation with the Department of Communications and Wave Propagation has developed a novel meshed satellite communications system which is optimised for Internet traffic and applications (L*IP—Local Network Interconnection via Satellite Systems Using the IP Protocol Suite). Both symmetrical and asymmetrical connections are supported. Bandwidth on demand and guaranteed quality of service are key features of the system. A novel multi-frequency TDMA access scheme utilises efficient methods of IP encapsulation. In contrast to other solutions it avoids legacy transport network techniques. While the DVB-RCS standard is based on ATM or MPEG transport cells, the solution of the L*IP system uses variable-length cells which reduces the overhead significantly. A flexible and programmable platform based on Linux machines was chosen to allow the easy implementation and adaptation to different standards. This offers the possibility to apply the system not only to satellite communications, but provides seamless integration with terrestrial fixed broadcast wireless access systems. The platform is also an ideal test-bed for a variety of interactive broadband communications systems. The paper describes the system architecture and the key features of the system.

  11. Shared broadcast channel for radio systems in the 2.4 GHz band

    NARCIS (Netherlands)

    Bekkaoui, Abdel; Haartsen, Jaap C.

    2005-01-01

    This paper presents a new collaborative mechanism for efficient coordination of radio communication devices, in particular addressing the unlicensed ISM band at 2.4 GHz. As the traffic in the ISM band is increasing tremendously, the potential for interference between uncoordinated devices is becomin

  12. Indoor radio channel modeling and mitigation of fading effects using linear and circular polarized antennas in combination for smart home system at 868 MHz

    Science.gov (United States)

    Wunderlich, S.; Welpot, M.; Gaspard, I.

    2014-11-01

    The markets for smart home products and services are expected to grow over the next years, driven by the increasing demands of homeowners considering energy monitoring, management, environmental controls and security. Many of these new systems will be installed in existing homes and offices and therefore using radio based systems for cost reduction. A drawback of radio based systems in indoor environments are fading effects which lead to a high variance of the received signal strength and thereby to a difficult predictability of the encountered path loss of the various communication links. For that reason it is necessary to derive a statistical path loss model which can be used to plan a reliable and cost effective radio network. This paper presents the results of a measurement campaign, which was performed in six buildings to deduce realistic radio channel models for a high variety of indoor radio propagation scenarios in the short range devices (SRD) band at 868 MHz. Furthermore, a potential concept to reduce the variance of the received signal strength using a circular polarized (CP) patch antenna in combination with a linear polarized antenna in an one-to-one communication link is presented.

  13. EPICS based low-level radio frequency control system in LIPAc

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, Julio, E-mail: julio.calvo@ciemat.es [Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Ciemat (Spain); Rivers, Mark L. [Department of Geophysical Sciences and Center for Advanced Radiation Sources, The University of Chicago (United States); Patricio, Miguel A. [Departamento de Informatica, Universidad Carlos III de Madrid (Spain); Ibarra, Angel [Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Ciemat (Spain)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer The system proposed can control amplitude and phase of each cavity. Black-Right-Pointing-Pointer Rapid diagnostics are refreshed in milliseconds. Black-Right-Pointing-Pointer Increasing control parameters will not increase consumed time neither complexity. Black-Right-Pointing-Pointer IQ demodulation can be achieved thanks to the transformed values at driver level. - Abstract: The IFMIF-EVEDA (International Fusion Materials Irradiation Facility - Engineering Validation and Engineering Design Activity) linear accelerator, known as Linear IFMIF Prototype Accelerator (LIPAc), will be a 9 MeV, 125 mA continuous wave (CW) deuteron accelerator prototype to validate the technical options of the accelerator design for IFMIF. The primary mission of such facility is to test and verify materials performance when subjected to extensive neutron irradiation of the type encountered in a fusion reactor to prepare for the design, construction, licensing and safe operation of a fusion demonstration reactor (DEMO). The radio frequency (RF) power system of IFMIF-EVEDA consists of 18 RF chains working at 175 MHz with three amplification stages each. The low-level radio frequency (LLRF) controls the amplitude and phase of the signal to be synchronized with the beam and it also controls the resonance frequency of the cavities. The system is based on a commercial compact peripheral component interconnect (cPCI) field programmable gate array (FPGA) board, provided by Lyrtech and controlled by a Windows host PC. For this purpose, it is mandatory to communicate the cPCI FPGA board from EPICS Channel Access [1]. A software architecture on EPICS framework in order to control and monitor the LLRF system is presented.

  14. The Radio Communication Project in Nepal: A Culture-Centered Approach to Participation

    Science.gov (United States)

    Dutta, Mohan Jyoti; Basnyat, Iccha

    2008-01-01

    Considerable research has been conducted on the topic of entertainment-education (EE), the method of using entertainment platforms such as popular music, radio, and television programming to diffuse information, attitudes, and behaviors via role modeling. A significant portion of the recently published EE literature has used the case of the Radio…

  15. 75 FR 46854 - Amendment of the Commission's Rules Regarding Amateur Radio Service Communications During...

    Science.gov (United States)

    2010-08-04

    ... the NPRM, public safety agencies and other emergency first responder entities voiced general support... radio. This integrative activity is essential to allow for a practiced response on the part of the first responder community in the event of an emergency. Because some of those drills and exercises include...

  16. 1Gbps impulse radio ultrawideband multi-hop system employing a single mode fiber repeater

    DEFF Research Database (Denmark)

    Yu, Xianbin; Rodes, Roberto; Jensen, Jesper Bevensee;

    2009-01-01

    We experimentally demonstrate a 1 Gbps impulse radio ultrawideband multi-hop system for wireless-over-fiber applications. The system consists of two 2 m air links and a 23 km single mode fiber based optical repeater......We experimentally demonstrate a 1 Gbps impulse radio ultrawideband multi-hop system for wireless-over-fiber applications. The system consists of two 2 m air links and a 23 km single mode fiber based optical repeater...

  17. A systems approach to animal communication.

    Science.gov (United States)

    Hebets, Eileen A; Barron, Andrew B; Balakrishnan, Christopher N; Hauber, Mark E; Mason, Paul H; Hoke, Kim L

    2016-03-16

    Why animal communication displays are so complex and how they have evolved are active foci of research with a long and rich history. Progress towards an evolutionary analysis of signal complexity, however, has been constrained by a lack of hypotheses to explain similarities and/or differences in signalling systems across taxa. To address this, we advocate incorporating a systems approach into studies of animal communication--an approach that includes comprehensive experimental designs and data collection in combination with the implementation of systems concepts and tools. A systems approach evaluates overall display architecture, including how components interact to alter function, and how function varies in different states of the system. We provide a brief overview of the current state of the field, including a focus on select studies that highlight the dynamic nature of animal signalling. We then introduce core concepts from systems biology (redundancy, degeneracy, pluripotentiality, and modularity) and discuss their relationships with system properties (e.g. robustness, flexibility, evolvability). We translate systems concepts into an animal communication framework and accentuate their utility through a case study. Finally, we demonstrate how consideration of the system-level organization of animal communication poses new practical research questions that will aid our understanding of how and why animal displays are so complex. © 2016 The Author(s).

  18. Tether enabled spacecraft systems for ultra long wavelength radio astronomy

    Science.gov (United States)

    Gemmer, Thomas; Yoder, Christopher D.; Reedy, Jacob; Mazzoleni, Andre P.

    2017-09-01

    This paper describes a proposed CubeSat mission to perform unique experiments involving interferometry and tether dynamics. A 3U CubeSat is to be placed in orbit where it will separate into three 1U CubeSats connected by a total of 100 m of tether. The separation between the three units will allow for the demonstration of high resolution radio interferometry. The increased resolution will provide access to the Ultra-Long Wavelength (ULW) scale of the electromagnetic spectrum, which is largely unexplored. During and after completion of the primary experiment, the CubeSat will be able to gather data on tethered dynamics of a space vehicle. Maneuvers to be performed and studied include direct testing of tether deployment and tethered formation flying. Tether deployment is a vital area where more data is needed as this is the phase where many tethered missions have experienced complications and failures. There are a large number of complex dynamical responses predicted by the theory associated with the deployment of an orbiting tethered system. Therefore, it is imperative to conduct an experiment that provides data on what dynamic responses actually occur.

  19. Compressed Measurements Based Spectrum Sensing for Wideband Cognitive Radio Systems

    Directory of Open Access Journals (Sweden)

    Taha A. Khalaf

    2015-01-01

    Full Text Available Spectrum sensing is the most important component in the cognitive radio (CR technology. Spectrum sensing has considerable technical challenges, especially in wideband systems where higher sampling rates are required which increases the complexity and the power consumption of the hardware circuits. Compressive sensing (CS is successfully deployed to solve this problem. Although CS solves the higher sampling rate problem, it does not reduce complexity to a large extent. Spectrum sensing via CS technique is performed in three steps: sensing compressed measurements, reconstructing the Nyquist rate signal, and performing spectrum sensing on the reconstructed signal. Compressed detectors perform spectrum sensing from the compressed measurements skipping the reconstruction step which is the most complex step in CS. In this paper, we propose a novel compressed detector using energy detection technique on compressed measurements sensed by the discrete cosine transform (DCT matrix. The proposed algorithm not only reduces the computational complexity but also provides a better performance than the traditional energy detector and the traditional compressed detector in terms of the receiver operating characteristics. We also derive closed form expressions for the false alarm and detection probabilities. Numerical results show that the analytical expressions coincide with the exact probabilities obtained from simulations.

  20. Interference Alignment and Fairness Algorithms for MIMO Cognitive Radio Systems

    Directory of Open Access Journals (Sweden)

    Feng Zhao

    2015-01-01

    Full Text Available Interference alignment (IA is an effective technique to eliminate the interference among wireless nodes. In a multiinput multi-output (MIMO cognitive radio system, multiple secondary users can coexist with the primary user without generating any interference by using the IA technology. However, few works have considered the fairness of secondary users. In this paper, not only is the interference eliminated by IA, but also the fairness of secondary users is considered by two kinds of algorithms. Without losing generality, one primary user and K secondary users are considered in the network. Assuming perfect channel knowledge at the primary user, the interference from secondary users to the primary user is aligned into the unused spatial dimension which is obtained by water-filling among primary user. Also, the interference between secondary users can be eliminated by a modified maximum signal-to-interference-plus-noise algorithm using channel reciprocity. In addition, two kinds of fairness algorithms, max-min fairness and proportional fairness, among secondary users are proposed. Simulation results show the effectiveness of the proposed algorithms in terms of suppressed interference and fairness of secondary nodes. What is more, the performances of the two fairness algorithms are compared.

  1. Split-aloha algorithm for radio frequency identification system

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Anti-Collision algorithm is one of the most important components of radio frequency identification (RFID) technology, which possesses a key position in the performance of the whole system. ALOHA algorithm is one of the most popular methods to solve the collision problem because of its efficiency and practicability. The grouping method has been developed for enhancing the performance of conventional ALOHA when there are thousands of tags. However, the existing grouping method has limitations in applications due to its rigorous requirements for the estimation of the number of backlog tags or the admirable characteristics of the tags' ID number. Working on the improvement of the grouping methods, we proposed an algorithm named split-ALOHA with a novel grouping method that split tags as a binary tree. The novel grouping method makes it more practicable than the existing grouping methods due to the simplified requirements for tags. Simulations of the proposed algorithm show the superior performance of a linearly increasing of the number of consumed time slots while the number of tags increases. The algorithm performance analysis between split-ALOHA and ALOHA algorithms with other grouping methods has been implemented in a proper way.

  2. Design of Measurement System for Determining the Radioclimatology Effect on the Radio Signal Propagation Using Universal Software Radio

    Directory of Open Access Journals (Sweden)

    Martin Tomis

    2013-01-01

    Full Text Available In this paper, a developed point-to-point wireless link using Universal Software Radio Peripheral (USRP is presented. The aim of the research is focused on the monitoring and analysing the transmission characteristics on the physical layer of such wireless communication link with the consideration that these parameters could be affected by atmospheric phenomenon and air pollution. For that reason, the wireless link is situated to heavily loaded environment of Ostrava agglomeration where it is assumed extreme atmospheric phenomena such as smog or inverse situation. In the next part, a developed application which perform a fully automatic long term measurement of the transmission characteristics using a wireless link is presented. Finally, the first experimental results based on mathematical regression are presented.

  3. Communication devices for network-hopping communications and methods of network-hopping communications

    Science.gov (United States)

    Buttles, John W

    2013-04-23

    Wireless communication devices include a software-defined radio coupled to processing circuitry. The system controller is configured to execute computer programming code. Storage media is coupled to the system controller and includes computer programming code configured to cause the system controller to configure and reconfigure the software-defined radio to operate on each of a plurality of communication networks according to a selected sequence. Methods for communicating with a wireless device and methods of wireless network-hopping are also disclosed.

  4. Development of an Experimental Phased Array Feed System and Algorithms for Radio Astronomy

    Science.gov (United States)

    Landon, Jonathan C.

    . Results are given for simulated and experimental data, demonstrating deeper beampattern nulls by 6 to 30dB. To increase the system bandwidth toward the hundreds of MHz bandwidth required by astronomers for a fully science-ready instrument, an FPGA digital backend is introduced using a 64-input analog-to-digital converter running at 50 Msamp/sec and the ROACH processing board developed at the University of California, Berkeley. International efforts to develop digital back ends for large antenna arrays are considered, and a road map is proposed for development of a hardware correlator/beamformer at BYU using three ROACH boards communicating over 10 gigabit Ethernet.

  5. The communication of meaning in social systems

    NARCIS (Netherlands)

    Leydesdorff, L.; Franse, S.

    2009-01-01

    The sociological domain is different from the psychological one insofar as meaning can be communicated at the supra-individual level. The computation of anticipatory systems enables us to distinguish between these domains in terms of weakly and strongly anticipatory systems with a structural

  6. Radio resource management using geometric water-filling

    CERN Document Server

    He, Peter; Zhou, Sheng; Niu, Zhisheng

    2014-01-01

    This brief introduces the fundamental theory and development of managing radio resources using a water-filling algorithm that can optimize system performance in wireless communication. Geometric Water-Filling (GWF) is a crucial underlying tool in emerging communication systems such as multiple input multiple output systems, cognitive radio systems, and green communication systems. Early chapters introduce emerging wireless technologies and provide a detailed analysis of water-filling. The brief investigates single user and multi-user issues of radio resource management, allocation of resources

  7. Communication Scheme via Cascade Chaotic Systems

    Institute of Scientific and Technical Information of China (English)

    HUA Chang-Chun; GUAN Xin-Ping

    2004-01-01

    @@ A new chaotic communication scheme is constructed. Different from the existing literature, cascade chaotic systems are employed. Two cascade modes are considered. First, we investigate the input to state cascade mode;cascade systems between different kinds of chaotic systems are considered. Then the parameter cascade case of chaotic system is studied. Under the different cases, the corresponding receivers are designed, which can succeed in recovering the former emitted signal. Simulations are performed to verify the validity of the proposed main results.

  8. Bandwidth utilization maximization of scientific RF communication systems

    Energy Technology Data Exchange (ETDEWEB)

    Rey, D. [Sandia National Lab., Albuquerque, NM (United States); Ryan, W. [New Mexico State Univ., Las Cruces, NM (United States); Ross, M.

    1997-01-01

    A method for more efficiently utilizing the frequency bandwidth allocated for data transmission is presented. Current space and range communication systems use modulation and coding schemes that transmit 0.5 to 1.0 bits per second per Hertz of radio frequency bandwidth. The goal in this LDRD project is to increase the bandwidth utilization by employing advanced digital communications techniques. This is done with little or no increase in the transmit power which is usually very limited on airborne systems. Teaming with New Mexico State University, an implementation of trellis coded modulation (TCM), a coding and modulation scheme pioneered by Ungerboeck, was developed for this application and simulated on a computer. TCM provides a means for reliably transmitting data while simultaneously increasing bandwidth efficiency. The penalty is increased receiver complexity. In particular, the trellis decoder requires high-speed, application-specific digital signal processing (DSP) chips. A system solution based on the QualComm Viterbi decoder and the Graychip DSP receiver chips is presented.

  9. Security Problem of Communication in CORBA System

    Directory of Open Access Journals (Sweden)

    Jedrzej Byrski

    2002-01-01

    Full Text Available CORBA standard defines the mechanisms of shearing services. The key rule plays ORB (Object Request Broker which enables location of suitable server and transparent communication between client and server: This paper presents problems connected with security during communication between ORB systems. In the CORBA system the objects are identified by IOR (Interoperable Object Reference. For T CP/IP it contains IP server address, port and object key. Filtration may use such information as: type of communicate, IP address of client, object key to which client wants to access, type of operation, clients principal. In proposed implementation the firewall works as CORBA server and cooperates with half bridge. It is registered in ORB system and provides the controlling functions for entering packages by IDL interface. In the paper also the structure of filtering module is presented. Its main part is ACL (Access Control Lisa with rules of access. The performance evaluation results are also presented.

  10. A Zynq-based Cluster Cognitive Radio

    OpenAIRE

    Rooks, Kurtis M.

    2014-01-01

    Traditional hardware radios provide very rigid solutions to radio problems. Intelligent software defined radios, also known as cognitive radios, provide flexibility and agility compared to hardware radio systems. Cognitive radios are well suited for radio applications in a changing radio frequency environment, such as dynamic spectrum access. In this thesis, a cognitive radio is demonstrated where the system self reconfigures to dem...

  11. Considerations about the Modeling of Software Defined Radio for Mobile Communications Networks

    Directory of Open Access Journals (Sweden)

    Lucian Morgos

    2009-05-01

    Full Text Available This paper presents the contribution of theauthors regarding the modeling of a software definedradio - SDR. The digital radios are base on ADCinterfaces that convert the base band signal in a digitalformat and a DSP that accomplish the demodulationaccording to a suitable digital processing algorithm. Totest the model the authors chosen a radio signal with aWeibull distribution quadrature amplitude modulationQAM that pass through a scattering medium till the RFfront end of the SDR. The fading effect was also takeninto consideration. The results of the demodulation usingthe proposed model of SDR were compared with aRayleigh distribution. The simulation results made by thehelp of MATLAB program emphasize the effects of thequantization levels of the ADC circuit.

  12. Deep Null Antennas and Their Applications to Tactical VHF Radio Communications

    Science.gov (United States)

    1989-03-01

    simulations must be carried out over less than perfect grounds. Reviev; of the Antenna Engineering Handbook . Vol. I [Ref. 6] provided the needed...means of getting the desired phase and magnitude relationships was not found, and as mentioned in the ARRL Antenna Book [Ret: 3: pp. 8-l-l], a number of...Englewood Cliffs, ::\\J, 1968. 3. American Radio Relay League, The ARRL Antenna Book, 15th ed., American Ra- dio Relay League, ~e,Yington, CT, 1988. 4

  13. Lymphangioma communicating with the excretory system.

    Science.gov (United States)

    Pancione, L; Giacomelli, G; Moroni, M; Taraglio, G; Mecozzi, B

    2008-03-01

    Lymphangioma is a rare benign tumor caused by failure in the development of the lymphatic communicating system. The corresponding nomenclature is confusing. In recent years ''renal lymphangiectasia'' is the preferred name. Although this disease may occur in any site of the body, the neck (75%) and axillary area (20%) are the most common sites, and the kidney is occasionally involved. We report a case of lymphangioma communicating with the urinary system in a 61-year-old man diagnosed by CT scan treated with nephrectomy and histological confirmation.

  14. Transceiver and system design for digital communications

    CERN Document Server

    Bullock, Scott

    2009-01-01

    Now in a 3rd edition, this successful book provides an intuitive approach to transceiver design, allowing a broad spectrum of readers to understand the topics clearly. It covers a wide range of data link communication design techniques, including link budgets, dynamic range and system analysis of receivers and transmitters used in data link communications, digital modulation and demodulation techniques of phase-shift keyed and frequency hopped spread spectrum systems using phase diagrams, multipath, gain control, an intuitive approach to probability, jamming reduction method using various adap

  15. Single Carrier Architecture for High Data Rate Wireless PAN Communications System

    CERN Document Server

    Rakotondrainibe, Lahatra; Zaharia, Gheorghe; Grunfelder, Guy; Zein, Ghaïs El

    2010-01-01

    A 60 GHz wireless Gigabit Ethernet (G.E.) communication system is developed at IETR. As the 60 GHz radio link operates only in a single-room configuration, an additional Radio over Fibre (RoF) link is used to ensure the communications in all the rooms of a residential environment. The realized system covers 2 GHz bandwidth. Due to the hardware constraints, a symbol rate at 875 Mbps is attained using simple single carrier architecture. In the baseband (BB) processing block, an original byte/frame synchronization process is designed to provide a smaller value of the preamble missing detection and false alarm probabilities. Bit error rate (BER) measurements have been realized in a large gym for line-of-sight (LOS) conditions. A Tx-Rx distance greater than 30 meters was attained with low BER using high gain antennas and forward error correction RS (255, 239) coding.

  16. Computationally Efficient Power Allocation Algorithm in Multicarrier-Based Cognitive Radio Networks: OFDM and FBMC Systems

    Science.gov (United States)

    Shaat, Musbah; Bader, Faouzi

    2010-12-01

    Cognitive Radio (CR) systems have been proposed to increase the spectrum utilization by opportunistically access the unused spectrum. Multicarrier communication systems are promising candidates for CR systems. Due to its high spectral efficiency, filter bank multicarrier (FBMC) can be considered as an alternative to conventional orthogonal frequency division multiplexing (OFDM) for transmission over the CR networks. This paper addresses the problem of resource allocation in multicarrier-based CR networks. The objective is to maximize the downlink capacity of the network under both total power and interference introduced to the primary users (PUs) constraints. The optimal solution has high computational complexity which makes it unsuitable for practical applications and hence a low complexity suboptimal solution is proposed. The proposed algorithm utilizes the spectrum holes in PUs bands as well as active PU bands. The performance of the proposed algorithm is investigated for OFDM and FBMC based CR systems. Simulation results illustrate that the proposed resource allocation algorithm with low computational complexity achieves near optimal performance and proves the efficiency of using FBMC in CR context.

  17. Computationally Efficient Power Allocation Algorithm in Multicarrier-Based Cognitive Radio Networks: OFDM and FBMC Systems

    Directory of Open Access Journals (Sweden)

    Shaat Musbah

    2010-01-01

    Full Text Available Cognitive Radio (CR systems have been proposed to increase the spectrum utilization by opportunistically access the unused spectrum. Multicarrier communication systems are promising candidates for CR systems. Due to its high spectral efficiency, filter bank multicarrier (FBMC can be considered as an alternative to conventional orthogonal frequency division multiplexing (OFDM for transmission over the CR networks. This paper addresses the problem of resource allocation in multicarrier-based CR networks. The objective is to maximize the downlink capacity of the network under both total power and interference introduced to the primary users (PUs constraints. The optimal solution has high computational complexity which makes it unsuitable for practical applications and hence a low complexity suboptimal solution is proposed. The proposed algorithm utilizes the spectrum holes in PUs bands as well as active PU bands. The performance of the proposed algorithm is investigated for OFDM and FBMC based CR systems. Simulation results illustrate that the proposed resource allocation algorithm with low computational complexity achieves near optimal performance and proves the efficiency of using FBMC in CR context.

  18. RF MEMS and Their Applications in NASA's Space Communication Systems

    Science.gov (United States)

    Williams, W. Daniel; Ponchak, George E.; Simons, Rainee N.; Zaman, Afroz; Kory, Carol; Wintucky, Edwin; Wilson, Jeffrey D.; Scardelletti, Maximilian; Lee, Richard; Nguyen, Hung

    2001-01-01

    Radio frequency (RF) and microwave communication systems rely on frequency, amplitude, and phase control circuits to efficiently use the available spectrum. Phase control circuits are required for electronically scanning phase array antennas that enable radiation pattern shaping, scanning, and hopping. Two types of phase shifters, which are the phase control circuits, are most often used. The first is comprised of two circuits with different phase characteristics such as two transmission lines of different lengths or a high pass and low pass filter and a switch that directs the RF power through one of the two circuits. Alternatively, a variable capacitor, or varactor, is used to change the effective electrical path length of a transmission line, which changes the phase characteristics. Filter banks are required for the diplexer at the front end of wide band communication satellites. These filters greatly increase the size and mass of the RF/microwave systems, but smaller diplexers may be made with a low loss varactor or a group of capacitors, a switch and an inductor.

  19. Wireless communication system via nanoscale plasmonic antennas.

    Science.gov (United States)

    Merlo, Juan M; Nesbitt, Nathan T; Calm, Yitzi M; Rose, Aaron H; D'Imperio, Luke; Yang, Chaobin; Naughton, Jeffrey R; Burns, Michael J; Kempa, Krzysztof; Naughton, Michael J

    2016-08-24

    Present on-chip optical communication technology uses near-infrared light, but visible wavelengths would allow system miniaturization and higher energy confinement. Towards this end, we report a nanoscale wireless communication system that operates at visible wavelengths via in-plane information transmission. Here, plasmonic antenna radiation mediates a three-step conversion process (surface plasmon → photon → surface plasmon) with in-plane efficiency (plasmon → plasmon) of 38% for antenna separation 4λ0 (with λ0 the free-space excitation wavelength). Information transmission is demonstrated at bandwidths in the Hz and MHz ranges. This work opens the possibility of optical conveyance of information using plasmonic antennas for on-chip communication technology.

  20. Wireless communication system via nanoscale plasmonic antennas

    Science.gov (United States)

    Merlo, Juan M.; Nesbitt, Nathan T.; Calm, Yitzi M.; Rose, Aaron H.; D'Imperio, Luke; Yang, Chaobin; Naughton, Jeffrey R.; Burns, Michael J.; Kempa, Krzysztof; Naughton, Michael J.

    2016-08-01

    Present on-chip optical communication technology uses near-infrared light, but visible wavelengths would allow system miniaturization and higher energy confinement. Towards this end, we report a nanoscale wireless communication system that operates at visible wavelengths via in-plane information transmission. Here, plasmonic antenna radiation mediates a three-step conversion process (surface plasmon → photon → surface plasmon) with in-plane efficiency (plasmon → plasmon) of 38% for antenna separation 4λ0 (with λ0 the free-space excitation wavelength). Information transmission is demonstrated at bandwidths in the Hz and MHz ranges. This work opens the possibility of optical conveyance of information using plasmonic antennas for on-chip communication technology.

  1. Investigate the Performance of LG 00 Mode in Cost Effective Hybrid Radio over Multimode Transmission System

    Directory of Open Access Journals (Sweden)

    Pardeep Kaur

    2014-05-01

    Full Text Available Radio over fiber (RoF technology composed for apprehension of future high performance integrated networks and future broadband networks. Multimode fiber links can offer a convenient approach for low cost and short Radio over Fiber (RoF systems. This work is based on the cost effective radio over multimode transmission system (Ro-MMF for long reach transmission. Error free transmission of 10 Gbps data with 10 GHz radio signal over multimode fiber link successfully demonstrated over 40 km. furthermore, The results are represented for Ro-MMF system by using LG (Laguerre-Gaussian 00 mode. The Performance of LG 00 mode in terms of SNR and Eye diagram investigated in proposed system.

  2. Formal indicators to assess the quality of radio systems perimeter security facilities

    Directory of Open Access Journals (Sweden)

    Kolesnik K. V.

    2012-08-01

    Full Text Available Quality estimation method based on the use of formal parameters, which greatly simplifies the process of creating effective radio systems for perimeter security of distributed objects in the design phase is proposed.

  3. Robust Stackelberg game in communication systems

    CERN Document Server

    parsaeefard, saeedeh; Sharafat, Ahmad R

    2011-01-01

    This paper studies multi-user communication systems with two groups of users: leaders which possess system information, and followers which have no system information using the formulation of Stackelberg games. In such games, the leaders play and choose their actions based on their information about the system and the followers choose their actions myopically according to their observations of the aggregate impact of other users. However, obtaining the exact value of these parameters is not practical in communication systems. To study the effect of uncertainty and preserve the players' utilities in these conditions, we introduce a robust equilibrium for Stackelberg games. In this framework, the leaders' information and the followers' observations are uncertain parameters, and the leaders and the followers choose their actions by solving the worst-case robust optimizations. We show that the followers' uncertain parameters always increase the leaders' utilities and decrease the followers' utilities. Conversely,...

  4. 多径分量噪声干扰下无线电扩频通信优化技术%Optimization of radio spread spectrum communication under multipath component noise interference

    Institute of Scientific and Technical Information of China (English)

    邸珩烨

    2016-01-01

    The radio spread spectrum communication is subjected to the interference of the multipath component noise, which leads to the poor communication channel equalization, the ability of anti interference is not strong, and the bit error rate is high. Noise interference suppression is needed to improve the quality of radio spread spectrum communication. An optimization technique of radio spread spectrum communication based on adaptive cascade notch and inter symbol interference suppression is proposed in the paper. The paper presents the construction of radio spread spectrum communication system transmission structure model, and selects an adaptive notch filter to decrease the noise of the spread spectrum radio multipath components, which reduces the signal access to in band interference power, improves the demodulator output signal⁃to⁃noise ratio and signal to stem ratio. With the expansion of the sequence to modulate the carrier, the signal is moved to the carrier frequency, furthermore channel equalization is realized , and anti⁃interference ability is improved. Simulation results show that the proposed algorithm can effectively reduce the bit error rate of spread spectrum communication, and improve the communication quality.%无线电扩频通信受到多径分量噪声的干扰,导致通信信道均衡性不好,抗干扰能力不强,误码率较高。需要进行噪声干扰抑制,改善无线电扩频通信质量。提出一种基于自适应级联陷波和码间干扰抑制的无线电扩频通信优化技术。构建无线电扩频通信系统传输结构模型,采用自适应陷波器对无线电扩频通信中的多径分量噪声进行有效抑制,降低了进入信号通频带内的干扰功率,提高解调器的输出信噪比和信干比。采用扩展后的序列去调制载波,将信号搬移到载频上,实现信道均衡,提高抗干扰能力。仿真结果表明,该算法能有效降低无线电扩频

  5. Secure Cooperative Spectrum Sensing via a Novel User-Classification Scheme in Cognitive Radios for Future Communication Technologies

    Directory of Open Access Journals (Sweden)

    Muhammad Usman

    2015-05-01

    Full Text Available Future communication networks would be required to deliver data on a far greater scale than is known to us today, thus mandating the maximal utilization of the available radio spectrum using cognitive radios. In this paper, we have proposed a novel cooperative spectrum sensing approach for cognitive radios. In cooperative spectrum sensing, the fusion center relies on reports of the cognitive users to make a global decision. The global decision is obtained by assigning weights to the reports received from cognitive users. Computation of such weights requires prior information of the probability of detection and the probability of false alarms, which are not readily available in real scenarios. Further, the cognitive users are divided into reliable and unreliable categories based on their weighted energy by using some empirical threshold. In this paper, we propose a method to classify the cognitive users into reliable, neutral and unreliable categories without using any pre-defined or empirically-obtained threshold. Moreover, the computation of weights does not require the detection, or false alarm probabilities, or an estimate of these probabilities. Reliable cognitive users are assigned the highest weights; neutral cognitive users are assigned medium weights (less than the reliable and higher than the unreliable cognitive users’ weights; and unreliable users are assigned the least weights. We show the performance improvement of our proposed method through simulations by comparing it with the conventional cooperative spectrum sensing scheme through different metrics, like receiver operating characteristic (ROC curve and mean square error. For clarity, we also show the effect of malicious users on detection probability and false alarm probability individually through simulations.

  6. 3rd International Conference on Communications, Signal Processing, and Systems

    CERN Document Server

    Liang, Qilian; Wang, Wei; Zhang, Baoju; Pi, Yiming

    2015-01-01

    The Proceedings of The Third International Conference on Communications, Signal Processing, and Systems provides the state-of-art developments of communications, signal processing, and systems. This book is a collection of contributions from the conference and covers such topics as wireless communications, networks, systems, and signal processing for communications. The conference was held July 2014 in Hohhot, Inner Mongolia, China.

  7. Mobile satellite communications for consumers

    Science.gov (United States)

    Noreen, Gary K.

    1991-11-01

    The RadioSat system based on MSAT satellites and scheduled for launch in 1994 is described. The RadioSat system will provide integrated communications and navigation services to consumers, including nationwide digital audio broadcasts, data broadcasts, precision navigation, and two-way voice and data communications. Particular attention is given to the MSAT satellite system capabilities and economics. It is concluded that the RadioSat system will be capable of providing a low-cost, highly flexible two-way communications for consumers that can be adapted to various applications.

  8. Compact Wireless Access Nodes for WDM Bidirectional Radio-over-Fiber System Based on RSOA

    DEFF Research Database (Denmark)

    Yu, Xianbin; Gibbon, Timothy Braidwood; Tafur Monroy, Idelfonso

    2009-01-01

    We demonstrate a RSOA based WDM radio-over-fiber, bidirectional system for wireless access networks. The multi-functionalities of a RSOA, such as colorless operation, re-modulation and envelope detection, make wireless access nodes more compact.......We demonstrate a RSOA based WDM radio-over-fiber, bidirectional system for wireless access networks. The multi-functionalities of a RSOA, such as colorless operation, re-modulation and envelope detection, make wireless access nodes more compact....

  9. Communications and Tracking Distributed Systems Evolution Study

    Science.gov (United States)

    Culpepper, William

    1990-01-01

    The Communications and Tracking (C & T) techniques and equipment to support evolutionary space station concepts are being analyzed. Evolutionary space station configurations and operational concepts are used to derive the results to date. A description of the C & T system based on future capability needs is presented. Included are the hooks and scars currently identified to support future growth.

  10. Manual communication systems: evolution and variation

    NARCIS (Netherlands)

    Pfau, R.; Pfau, R.; Steinbach, M.; Woll, B.

    2012-01-01

    This chapter addresses issues in the evolution and typology of manual communication systems. From a language evolution point of view, sign languages are interesting because it has been suggested that oral language may have evolved from gestural (proto)language. As far as typology is concerned, two i

  11. A system dynamics model for communications networks

    Science.gov (United States)

    Awcock, A. J.; King, T. E. G.

    1985-09-01

    An abstract model of a communications network in system dynamics terminology is developed as implementation of this model by a FORTRAN program package developed at RSRE is discussed. The result of this work is a high-level simulation package in which the performance of adaptive routing algorithms and other network controls may be assessed for a network of arbitrary topology.

  12. Transforming student learning with classroom communication systems

    CERN Document Server

    Beatty, I D

    2005-01-01

    Since 1993, the University of Massachusetts Physics Education Research Group (UMPERG) has developed curriculum and pedagogic techniques for use with classroom communication systems (CCSs) and has researched the effectiveness of CCS-based teaching. This bulletin describes how CCSs can influence "interactive pedagogy" and fundamentally transform the learning process. It includes advice drawn from lessons learned through a decade of experience.

  13. All optical up-converted signal generation with high dispersion tolerance using frequency quadrupling technique for radio over fiber system

    Science.gov (United States)

    Gu, Yiying; Zhao, Jiayi; Hu, Jingjing; Kang, Zijian; Zhu, Wenwu; Fan, Feng; Han, Xiuyou; Zhao, Mingshan

    2016-05-01

    A novel all optical up-converted signal generation scheme with optical single-sideband (OSSB) technique for radio over fiber (RoF) application is presented and experimentally demonstrated using low-bandwidth devices. The OSSB signal is generated by one low-bandwidth intensity LiNbO3 Mach-Zehnder modulator (LN-MZM) under frequency quadrupling modulation scheme and one low-bandwidth LN-MZM under double sideband carrier suppressed modulation (DSB-CS) scheme. The proposed all OSSB generation scheme is capable of high tolerance of fiber chromatic dispersion induced power fading (DIPF) effect. Benefiting from this novel OSSB generation scheme, a 26 GHz radio frequency (RF) signal up-conversion is realized successfully when one sideband of the optical LO signal is reused as the optical carrier for intermediate frequency (IF) signal modulation. The received vector signal transmission over long distance single-mode fiber (SMF) shows negligible DIPF effect with the error vector magnitude (EVM) of 15.7% rms. In addition, a spurious free dynamic range (SFDR) of the OSSB up-converting system is measured up to 81 dB Hz2/3. The experiment results indicate that the proposed system may find potential applications in future wireless communication networks, especially in microcellular personal communication system (MPCS).

  14. Effects of personality on territory defence in communication networks: a playback experiment with radio-tagged great tits.

    Science.gov (United States)

    Amy, Mathieu; Sprau, Philipp; de Goede, Piet; Naguib, Marc

    2010-12-07

    Individuals often differ consistently in behaviour across time and contexts, and such consistent behavioural differences are commonly described as personality. Personality can play a central role in social behaviour both in dyadic interactions and in social networks. We investigated whether explorative behaviour, as proxy of personality of territorial male great tits (Parus major), predicts their own and their neighbours' territorial responses towards simulated intruders. Several weeks prior to playback, subjects were taken from the wild to test their exploratory behaviour in a standard context in the laboratory. Exploratory behaviour provides a proxy of personality along a slow-fast explorer continuum. Upon release, males were radio-tracked and subsequently exposed to interactive playback simulating a more or a less aggressive territorial intruder (by either overlapping or alternating broadcast songs with the subjects' songs). At the same time, we radio-tracked a neighbour of the playback subject. Male vocal responses during playback and spatial movements after playback varied according to male explorative behaviour and playback treatment. Males with lower exploration scores approached the loudspeaker less, and sang more songs, shorter songs and songs with slower element rates than did males with higher exploration scores. Moreover, neighbour responses were related to the explorative behaviour of the subject receiving the playback but not to their own explorative behaviour. Our overall findings reveal for the first time how personality traits affect resource defence within a communication network providing new insights on the cause of variation in resource defence behaviour.

  15. Enhancing Radio Access Network Performance over LTE-A for Machine-to-Machine Communications under Massive Access

    Directory of Open Access Journals (Sweden)

    Fatemah Alsewaidi

    2016-01-01

    Full Text Available The expected tremendous growth of machine-to-machine (M2M devices will require solutions to improve random access channel (RACH performance. Recent studies have shown that radio access network (RAN performance is degraded under the high density of devices. In this paper, we propose three methods to enhance RAN performance for M2M communications over the LTE-A standard. The first method employs a different value for the physical RACH configuration index to increase random access opportunities. The second method addresses a heterogeneous network by using a number of picocells to increase resources and offload control traffic from the macro base station. The third method involves aggregation points and addresses their effect on RAN performance. Based on evaluation results, our methods improved RACH performance in terms of the access success probability and average access delay.

  16. System Control Applications of Low-Power Radio Frequency Devices

    Science.gov (United States)

    van Rensburg, Roger

    2017-09-01

    This paper conceptualizes a low-power wireless sensor network design for application employment to reduce theft of portable computer devices used in educational institutions today. The aim of this study is to design and develop a reliable and robust wireless network that can eradicate accessibility of a device’s human interface. An embedded system supplied by an energy harvesting source, installed on the portable computer device, may represent one of multiple slave nodes which request regular updates from a standalone master station. A portable computer device which is operated in an undesignated area or in a field perimeter where master to slave communication is restricted, indicating a possible theft scenario, will initiate a shutdown of its operating system and render the device unusable. Consequently, an algorithm in the device firmware may ensure the necessary steps are executed to track the device, irrespective whether the device is enabled. Design outcomes thus far indicate that a wireless network using low-power embedded hardware, is feasible for anti-theft applications. By incorporating one of the latest Bluetooth low-energy, ANT+, ZigBee or Thread wireless technologies, an anti-theft system may be implemented that has the potential to reduce major portable computer device theft in institutions of digitized learning.

  17. Impact of cognitive radio on radio astronomy

    NARCIS (Netherlands)

    Bentum, M.J.; Boonstra, A.J.; Baan, W.A.

    2010-01-01

    The introduction of new communication techniques requires an increase in the efficiency of spectrum usage. Cognitive radio is one of the new techniques that fosters spectrum efficiency by using unoccupied frequency spectrum for communications. However, cognitive radio will increase the transmission

  18. Second International Conference on Communications, Signal Processing, and Systems

    CERN Document Server

    Mu, Jiasong; Wang, Wei; Liang, Qilian; Pi, Yiming

    2014-01-01

    The Proceedings of The Second International Conference on Communications, Signal Processing, and Systems provides the state-of-art developments of Communications, Signal Processing, and Systems. The conference covered such topics as wireless communications, networks, systems, signal processing for communications. This book is a collection of contributions coming out of The Second International Conference on Communications, Signal Processing, and Systems (CSPS) held September 2013 in Tianjin, China.

  19. Radio Data System-Platform for traffic and travel information services

    Directory of Open Access Journals (Sweden)

    Claudiu Dan BARCA

    2017-03-01

    Full Text Available In the current National and European context where the public information is simultaneously spread on multiple channels and especially through mass-media channels, the text messaging services from public radio channels proved to be very useful and efficient for this purpose. Over the years, the use of a warning system like Radio Data System (RDS, at a global level shown, through text message or sound alarms is useful for the drivers to know the traffic, as well as for being aware of any emergency situations (fires, floods, earth-quakes. In this paper we present the characteristics of an RDS system with the Alert feature, as well as the study of radio covering of four from the Romanian National Radio News network's broadcasting points.

  20. System and method for phase retrieval for radio telescope and antenna control

    Science.gov (United States)

    Dean, Bruce H. (Inventor)

    2013-01-01

    Disclosed herein are systems, methods, and non-transitory computer-readable storage media for radio phase retrieval. A system practicing the method gathers first data from radio waves associated with an object observed via a first aperture, gathers second data from radio waves associated with the object observed via an introduced second aperture associated with the first aperture, generates reduced noise data by incoherently subtracting the second data from the first data, and performs phase retrieval for the radio waves by modeling the reduced noise data using a single Fourier transform. The first and second apertures are at different positions, such as side by side. This approach can include determining a value Q which represents a ratio of wavelength times a focal ratio divided by pixel spacing. This information can be used to accurately measure and correct alignment errors or other optical system flaws in the apertures.