Cooperative Diversity in Wireless Networks: Randomization over Dispersive Channels

Abstract

Recently, cooperative communications have been widely acknowledged as a virtual multi-antenna system that resolves the size or hardware limitations at transmitter. We develop randomized cooperation and analyze its diversity protocols that combat fading induced by multi-path propagation in wireless networks. Decentralized cooperation with randomized space-time coding exploits both spatial and temporal diversity available through cooperating users' relaying signals and sharing single antenna mutually. With several randomization techniques introduced, we study performance characterizations in terms of symbol error probability, which measures robustness of the transmissions to fading, focusing on the high signal-to-noise (SNR) regime. We also show that the cooperative diversity analysis is theoretically and numerically suitable even for frequency selective channels.