Multiuser Diversity in Multiuser Two-Hop Cooperative Relay Wireless Networks: System Model and Performance Analysis

Cooperative communications significantly improve the performance of wireless networks with the help of relay nodes, whereas multiuser diversity (MUD) is a kind of diversity inherent in multiuser systems. In this paper, we present a framework to analyze the performance of MUD in the multiuser two-hop cooperative relay networks (TCRNs). Based on this framework, we derive tight closed-form expressions of outage probability and symbol error probability (SEP) for the amplify-and-forward (AF), fixed decode-and-forward (DF), and selective DF protocols with MUD. Both the theoretical analysis and simulations show that in multiuser TCRNs, MUD orders of 2K, K, and 2K can be achieved for AF, fixed DF, and selective DF, respectively (where K is the number of users).