SER Performance Analysis and Power Allocation for Amplify-and-Forward Relay Networks

In this paper, we analyze the symbol-error-rate (SER) performance for a two-user amplify-and-forward cooperative system. The closed-form SER formulation with PSK signals is derived first, a upper bound is established to show the asymptotic performance of the cooperation protocol which is tight at high signal-to-noise ratio (SNR). Moreover, we develop an optimum power allocation method (OPA) for the cooperative system to minimize the SER. It turns out that this OPA method does not depend on the direct link between source and destination, it depends only on the channel links related to the relay. We also find that the SER performance is better when the relay is near the destination with OPA method.