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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
351

On multiple-antenna communications: signal detection, error exponent and and quality of service

Li, Qiang 10 October 2008 (has links)
Motivated by the demand of increasing data rate in wireless communication, multiple-antenna communication is becoming a key technology in the next generation wireless system. This dissertation considers three different aspects of multipleantenna communication. The first part is signal detection in the multiple-input multiple-output (MIMO) communication. Some low complexity near optimal detectors are designed based on an improved version of Bell Laboratories Layered Space-Time (BLAST) architecture detection and an iterative space alternating generalized expectation-maximization (SAGE) algorithm. The proposed algorithms can almost achieve the performance of optimal maximum likelihood detection. Signal detections without channel knowledge (noncoherent) and with co-channel interference are also investigated. Novel solutions are proposed with near optimal performance. Secondly, the error exponent of the distributed multiple-antenna communication (relay) in the windband regime is computed. Optimal power allocation between the source and relay node, and geometrical relay node placement are investigated based on the error exponent analysis. Lastly, the quality of service (QoS) of MIMO/single-input single- output(SISO) communication is studied. The tradeoff of the end-to-end distortion and transmission buffer delay is derived. Also, the SNR exponent of the distortion is computed for MIMO communication, which can provide some insights of the interplay among time diversity, space diversity and the spatial multiplex gain.
352

Space-Time-Frequency 3-Dimensional Complementary Coded CDMA Systems

Wu, Cheng-Lung 10 September 2007 (has links)
none
353

Study of Channel Estimation in MIMO-OFDM for Software Defined Radio

Wang, Qi January 2007 (has links)
<p>The aim of the thesis is to find out the most suitable channel estimation algorithms for the existing MIMO-OFDM SDR platform. Starting with the analysis of several prevalent channel estimation algorithms, MSE performance are compared under different scenarios. As a result of the hardware independent analysis, the complexvalued matrix computations involved in the algorithms are decomposed to real FLoating-point OPerations (FLOPs). Four feasible algorithms are selected for hardware dependent discussion based on the proposed hardware architecture. The computational latency is exposed as a manner of case study.</p>
354

Estimation de canal pour systèmes multi-antennes multi-porteuses

Le Saux, Benoît 25 October 2007 (has links) (PDF)
L'objectif des travaux réalisés dans le cadre de cette thèse est d'étudier et de proposer des schémas d'estimation de canal dans un contexte multi-antennes multiporteuses sur canal de transmission radio-mobile. L'estimation de canal constitue un point clé dans les performances d'un système de transmission et en particulier pour un système multi-antennes ou MIMO : elle doit être optimisée pour conserver les avantages de la technologie MIMO en termes de d´ebit et de performance. Ainsi, pour une transmission MIMO-OFDM, afin d'égaliser le signal reçu, le récepteur doit estimer non plus un seul canal comme dans un cas mono-antenne mais un ensemble de sous-canaux constituant le canal MIMO. De plus, cette estimation nécessite dans la majorité des cas une insertion dans la trame de symboles connus ce qui entraîne une diminution de l'efficacité spectrale. A l'émission, nous montrons que la construction des trames et plus particulièrement la position des symboles pilotes nécessaires à l'estimation de canal doit tenir compte du nombre d'antennes à l'émission. En réception, l'interpolation des coefficients obtenus soit grâce aux symboles pilotes soit grâce aux données estimées n'est efficace qu'en utilisant les corrélations temporelle et/ou fréquentielle des sous-canaux. Afin de s'affranchir de la connaissance de certaines propriétés du canal en réception, plusieurs estimateurs robustes vis-à-vis des sélectivités présentées par les sous-canaux sont proposés. Ces estimateurs traitent efficacement les symboles pilotes et ont été intégrés dans un processus itératif en réception. Les techniques de construction de trame ainsi que les estimateurs de canal proposés sont optimisés dans notre étude selon plusieurs critères : robustesse vis-à-vis des sélectivités, efficacité spectrale, complexité en émission et en réception. Les résultats de simulation obtenus pour différents contextes MIMO montrent une amélioration des techniques d'estimation de canal.
355

A software defined radio approach for high data rate multi-antenna wireless communications with frequency domain processing

Wilzeck, Andreas January 2009 (has links)
Zugl.: Hannover, Univ., Diss., 2009
356

A study on low complexity near-maximum likelihood spherical MIMO decoders

Liang, Ying, January 2010 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 59-61). Also available in print.
357

Architectures for symbol timing synchronization in MIMO communications /

Liu, Kejing, January 2004 (has links) (PDF)
Thesis (M.S.)--Brigham Young University. Dept. of Electrical and Computer Engineering, 2004. / Includes bibliographical references (p. 57-59).
358

Design and analysis of wireless communication systems with limited CSIT feedback /

Wu, Tianyu. January 2009 (has links)
Includes bibliographical references (p. 124-131).
359

Achieving near-optimal MIMO capacity in a rank-deficient LOS environment

Walkenhorst, Brett T. January 2009 (has links)
Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Ingram, Mary Ann; Committee Member: Durgin, Greg; Committee Member: Kenney, Steve; Committee Member: Landgren, Jack; Committee Member: Li, Ye. Part of the SMARTech Electronic Thesis and Dissertation Collection.
360

A study of channel estimation for OFDM systems and system capacity forMIMO-OFDM systems

Zhou, Wen, 周雯 January 2010 (has links)
published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

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