Sökning: "fading"

Visar resultat 16 - 20 av 205 avhandlingar innehållade ordet fading.

  1. 16. On MIMO Systems and Adaptive Arrays for Wireless Communication : Analysis and Practical Aspects

    Författare :Mattias Wennström; Michael A. Jensen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Systemteknik; antenna array; calibration; MIMO system; flat fading; non-linear amplifier; switched parasitic antenna; analog beamformer; adaptive antenna testbed; Systemteknik; Systems engineering; Systemteknik; Signal Processing; signalbehandling;

    Sammanfattning : This thesis is concerned with the use of multiple antenna elements in wireless communication over frequency non-selective radio channels. Both measurement results and theoretical analysis are presented. New transmit strategies are derived and compared to existing transmit strategies, such as beamforming and space-time block coding (STBC). LÄS MER

  3. 17. Convolutional Codes for Wireless Packet Data Systems

    Författare :Sorour Falahati; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; tailbiting coding; rate compatible punctured convolutional codes; adaptive modulation system; hybrid type-II ARQ; Rayleigh fading.;

    Sammanfattning : Automatic Repeat reQuest (ARQ) schemes can guarantee an almost error freereception strongly required in data communications. Hybrid type-II ARQschemes are supplied with channel coding to further improve the performance.In these schemes, error correction is performed adaptively which makesthem favorable for applications in time varying channels. LÄS MER

  4. 18. On Receiver Algorithms for OFDM Systems

    Författare :Florent Munier; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quantisation; multicarrier modulation; Intercarrier Interference ICI ; Phase noise; Wiener process; orthogonal frequency division multiplexing OFDM ; estimation; fading channels; channel estimation; iterative decoding.;

    Sammanfattning : This thesis addresses the problem of designing a receiver for an Orthogonal FrequencyDivisionMultiplexing (OFDM)communication system operating over fading channels, taking into account the effects of hardware imperfections. We discuss solutions for efficiently estimating the parameters of a channel model and for compensating oscillator phase noise and analog to digital converter (ADC) quantisation errors at the receiver. LÄS MER

  5. 19. Rate adaption for progressively encoded video over fading AWGN channels

    Författare :Martin Sehlstedt; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Signal Processing;

    Sammanfattning : With the increased capacity of the Internet it is possible to use it for real-time multimedia applications, such as video conferences. There is also an increasing interest in using Internet technology in cellular networks, such as mobile phones. LÄS MER

  7. 20. Communication-Aware Motion Planning for Mobile Robots

    Författare :Magnus Minnema Lindhé; Karl Henrik Johansson; Francesco Bullo; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; autonomous systems; robotics; wireless sensor networks; motion planning; multipath fading;

    Sammanfattning : Mobile robots have found numerous applications in recent years, in areas such as consumer robotics, environmental monitoring, security and transportation. For information dissemination, multi-robot cooperation or operator intervention, reliable communications are important. LÄS MER