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Transceiver optimization for broadband cooperative wireless communication systems

University of British Columbia

Cooperative broadband communications is a promising technique to improve the reliability, throughput, and coverage of the next generation wireless communication systems. Single-carrier transmission with frequency-domain equalization (SC-FDE) and orthogonal frequency-division multiplexing (OFDM) are the prevailing block based broadband schemes widely adopted in major wireless standards. Traditionally, these broadband schemes are deployed for point-to-point communications without the cooperation of any intermediate transmission nodes. However, as the communication systems evolve, both service providers and users are demanding higher data rates and non-seamless connection over large areas. As a result, it is necessary to design novel transceiver architectures that meet these stringent requirements. This dissertation proposes four such cooperative transceiver designs which are tailored for different communication scenarios. Firstly, for single-user SC-FDE broadband systems with multiple multi-antenna amplify-and-forward (AF) relays, we optimize the relay beamforming (rBF) filters and destination equalization filter based on the minimum mean-square error (MSE) criterion under an aggregate relay transmit power constraint. We also propose suboptimal rBF schemes which perform close to the optimal rBF scheme. Subsequently, we investigate single-user SC-FDE broadband MIMO AF relay systems. By exploiting the properties of the block-circulant channel matrices and the majorization theory, the problem is transformed into an equivalent power optimization problem with scalar variables. An alternating optimization algorithm is devised to obtain the optimal solution for the source and relay power allocation. Thirdly, we study a robust transceiver design for multiuser broadband systems with multiple single-antenna AF relays and in the presence of channel estimation errors. Our proposed design treats multiuser SC-FDE and OFDM based systems in a unified manner, where the goal is to maximize the network ABR subject to different types of relay power constraints. Lastly, we propose a robust transceiver design for single-user SC-FDE based multi-hop full-duplex decode-and-forward relay systems. The optimization problem is formulated as the minimization of the sum MSE or maximum MSE of different hops which takes into account the loopback interference of the full-duplex relays. We propose two algorithms to solve the resulting non-convex power allocation problems based on sequential geometric programming and alternating optimization, respectively.

Text

2015-11-05

Attribution-NonCommercial-NoDerivs 2.5 Canada

http://hdl.handle.net/2429/55220

Electrical and Computer Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/2.5/ca/