Sökning: "Rayleigh-fading channels"

Visar resultat 1 - 5 av 37 avhandlingar innehållade orden Rayleigh-fading channels.

  1. 1. Detection principles for fast Rayleigh fading channels using an antenna array

    Författare :Anders Hansson; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; iterative decoding; serially concatenated coding; adaptive antenna arrays; multiple antennas; APP algorithm; diversity reception; Rayleigh channels; correlation; sequence detection; fading channels;

    Sammanfattning : .... LÄS MER

  3. 2. Short-Packet Communications: Fundamental Performance and Key Enablers

    Författare :Johan Östman; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; Rayleigh fading; Block-fading channels; Rician fading; variable-length stop-feedback; short-packet channel codes.; ultra-reliable low-latency;

    Sammanfattning : The paradigm shift from 4G to 5G communications, predicted to enable new use cases such as ultra-reliable low-latency communications (URLLC), will enforce a radical change in the design of communication systems. Unlike in 4G systems, where the main objective is to have a large transmission rate, in URLLC, as implied by its name, the objective is to enable transmissions with low latency and, simultaneously, very high reliability. LÄS MER

  4. 3. Channel Related Optimization of Wireless Communication Systems

    Författare :Fredrik Tufvesson; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; time division duplex; multicarrier; Radio communication; orthogonal frequency division multiplex; channel estimation; pilot symbol assisted modulation; sub-channel spacing; sub-channel bandwidth; interchannel interference; cyclic prefix; intersymbol interference; Rayleigh fading; precoding; pre-compensation;

    Sammanfattning : This thesis deals with different optimization problems in the design of wireless communication systems. It is mainly directed to the design of systems based on multicarrier techniques and orthogonal frequency division multiplex, OFDM, but some of the problems apply to single carrier systems as well. LÄS MER

  5. 4. Multirate Codes and Multicarrier Modulation for Future Communication Systems

    Författare :Pål Frenger; Chalmers University of Technology; []
    Nyckelord :channel estimation; code-spread CDMA; DS-CDMA; convolutional codes; interference cancellation; nested convolutional codes; multicarrier modulation; optimum distance spectrum ODS ; rate-compatible punctured convolutional codes RCPC-codes ; OFDM; turbo decoding; rate matching; parallel combinatory signaling; Rayleigh fading;

    Sammanfattning : In this thesis, new detection and modulation methods for multicarrier systems are presented. The proposed multicarrier detectors are based on feedback of previously detected symbols and the idea is to exploit the correlation, both in time between consecutive symbols, and in frequency between neighboring sub-carriers. LÄS MER

  7. 5. Convolutional Codes for Wireless Packet Data Systems

    Författare :Sorour Falahati; Chalmers University of Technology; []
    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