Effect of fading correlation on the performance of cooperative systems with multi relay nodes

Research on cooperative communication has revealed potential benefits from employing this technique in wireless networks. However, most of the work in this field pays little attention to the impact of correlation on the performance achieved. In this paper, the effect of fading correlation on the mutual information of a cooperative communication system with multiple relay nodes is investigated. A generalised channel model is adopted in the investigation, in order to address the asymmetric property of the variances of fading coefficients in different wireless channels. Simulation results show that correlation can have a positive, negative, or limited effect on mutual information of the systems employing the space-time-code based decode-forward protocol, depending on the circumstances involved. This is mainly because correlation has affected the way relay nodes participate in cooperative transmission.