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Hittade 3 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. 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

  3. 2. Cross-layer Aspects in OFMDA Systems : Feedback, Scheduling and Beamforming

    Författare :Patrick Svedman; Björn Ottersten; Ana I. Pérez-Neira; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Telecommunication; Telekommunikation;

    Sammanfattning : This thesis mainly studies the downlink of a wireless multiuser system, where the transmitter has limited knowledge about the communication channels of the users. Key techniques to improve the performance of such systems are, for instance, multiple antennas, multiuser diversity and orthogonal frequency-division multiple access (OFDMA). LÄS MER

  4. 3. Robust Transmit Signal Design and Channel Estimation for Multiantenna Systems

    Författare :Nafiseh Shariati; Mats Bengtsson; Ana I. Pérez-Neira; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : In the development of advanced signal processing techniques, dealing with both uncertainties and computational burden is essential. Taking the uncertainties into consideration is required in order to guarantee a certain level of performance, even when the system is designed based on imperfect prior knowledge. LÄS MER