Sökning: "HARQ."

Visar resultat 1 - 5 av 9 avhandlingar innehållade ordet HARQ..

  1. 1. Ultra-Reliable Short-Packet Communications: Fundamental Limits and Enabling Technologies

    Författare :Johan Östman; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ultra-reliable low-latency; variablelength stop-feedback; imperfect CSI; channel estimation; HARQ.; joint detection and decoding; short packets; Block-fading channels; multiuser massive MIMO;

    Sammanfattning : The paradigm shift from 4G to 5G communications, anticipated to enable ultra-reliable low-latency communications (URLLC), will enforce a radical change in the design of wireless communication systems. Unlike in 4G systems, where the main objective is to provide 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

  3. 2. HARQ Systems: Resource Allocation, Feedback Error Protection, and Bits-to-Symbol Mappings

    Författare :Chaitanya Tumula V. K.; Erik G. Larsson; Danyo Danev; Ana I. Pérez-Neira; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HARQ Systems; Resource Allocation; Geometric Programming; 3GPP-LTE; PUCCH Format 2; Complex-field coding; Signal Space Diversity; Optimization; Superposition Coding;

    Sammanfattning : Reliability of data transmission is a fundamental problem in wireless communications. Fading in wireless channels causes the signal strength to vary at the receiver and this results in loss of data packets. To improve the reliability, automatic repeat request (ARQ) schemes were introduced. LÄS MER

  4. 3. Predictor Antenna Systems: Exploiting Channel State Information for Vehicle Communications

    Författare :Hao Guo; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 6G; Beyond 5G; temporal correlation; spatial correlation; wireless backhaul; outage probability; hybrid automatic repeat request HARQ ; channel state information CSI ; throughput; integrated access and backhaul IAB ; mobile relay; predictor antenna PA ; mobility; Marcum Q-function; relay; rate adaptation;

    Sammanfattning : Vehicle communication is one of the most important use cases in the fifth generation of wireless networks (5G).  The growing demand for quality of service (QoS) characterized by performance metrics, such as spectrum efficiency, peak data rate, and outage probability, is mainly limited by inaccurate prediction/estimation of channel state information (CSI) of the rapidly changing environment around moving vehicles. LÄS MER

  5. 4. Data Transmission in the Presence of Limited Channel State Information Feedback

    Författare :Behrooz Makki; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Channel state information; Outage probability; Long-term throughput; Continuous communication; Feedback compression; Hybrid automatic repeat request HARQ ; Green communication; Bursty communication; Adaptive power allocation; CSI quantization; Block-fading channels; Correlated fading channels;

    Sammanfattning : .... LÄS MER

  7. 5. Adaptive Concatenated Coding for Wireless Real-Time Communications

    Författare :Elisabeth Uhlemann; Högskolan i Halmstad; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Incremental redundancy hybrid ARQ; Multiple concatenated codes; Iterative decoding; Rate compatible punctured codes; Union bounds; EXIT charts; Convergence analysis; Wireless real-time communication; Quality of service; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : The objective of this thesis is to improve the performance of real-time communication overa wireless channel, by means of specifically tailored channel coding. The deadlinedependent coding (DDC) communication protocol presented here lets the timeliness and thereliability of the delivered information constitute quality of service (QoS) parametersrequested by the application. LÄS MER