Performance of L-branch diversity combiners in equally correlated Rician fading channels

Despite the importance of the Rician fading model in describing microcellular, picocellular and mobile satellite channels, few theoretical results are known about the performance of selection combining (SC) and equal gain combining (EGC) in correlated Rician fading channels. In this paper, we develop a novel approach for performance analysis of L-branch diversity systems in equally correlated Rician fading channels. This approach involves transforming a set of equally correlated branch gains into a set of conditionally independent branch gains, analyzing the performance for the independent case and averaging the conditional results. Consequently, we derive novel expressions for the average error rates of various digital modulations and the output moments for both SC and EGC. We find that the performance of diversity systems in correlated Rician fading channels can be worse than that in correlated Rayleigh fading channels, which has never been observed for the independent fading case.