Performance Analysis of Distributed Spatial Diversity with Selection Combining

Cooperative diversity, where multiple communication nodes collaborate to exploit independent signal replicas that are combined at the destination has been proposed. Practical diversity receivers often employ simple combining techniques especially if comparable performance to more complex optimum combining can be achieved. The performances of cooperative diversity systems that use selection combining are investigated. In particular, we consider decode-and-forward and amplify- and-forward relaying protocols. Closed-form expressions for the outage probability of systems with an arbitrary number of relay nodes are derived. By comparing the performance of a system that uses selection combining to one that uses optimum maximal ratio combining, the trade-off between performance and receiver complexity is determined.