Impact of Relay Location According to SER for Amplify-and-Forward Cooperative Communications

In this paper, we analyze the symbol-error-rate (SER) performance for a two-user amplify-and-forward cooperative system. By making use of M-PSK modulation, the closed-form SER formulation and corresponding upper bound are derived first. According to the SER performance analysis, the impact of relay location is discussed by making use of a simple line topology. If the power allocation to the source and relay is equal, we can draw an interesting conclusion that the SER performance in such topology shows a symmetry property and the optimum relay location is just in the middle with respect to the source and destination.