Link adaptive relaying with virtual noise based detection in cooperative wireless networks

Wireless cooperative communications has recently gained significant attention since it provides spatial diversity and performance gain over conventional systems by eliminating the requirement of locating physical antenna arrays at terminals. In this thesis, a scheme that combines link adaptive relaying (LAR) and virtual noise (VN) modeling based detection techniques which have been introduced in the literature to prevent performance degradation in decode and forward based cooperative wireless networks due to error propagation is proposed and its error performance is investigated for Nakagami-m and Rician fading channels. The communication protocol under consideration builds upon orthogonal decode-and-forward relaying where the source terminal communicates with the relay and destination in the first phase and the second phase is allocated for transmission of the estimated data block of the source from the relay to destination. It has been shown that the proposed system (LAR with VN) provides significant performance improvement in various situations with respect to the classcial LAR structures with MRC in which maximal ratio combining is employed at the destination.