Symbol error rate of selective cooperation in Nakagami-m environments

In this paper, we present asymptotic symbol error rate (SER) analysis for selective amplify-and-forward (AF) cooperative systems with arbitrary number of relays. Any relay channel involved experiences independent and non-identically distributed Nakagami-m fading. Due to the complicated form of the probability density function (PDF) of the instantaneous dual-hop link signal-to-noise ratio (SNR), we provide its tight approximation at high SNR regions. The result reveals that the dual-hop relay link is dominated by the more severely fading hop and is extendable to multiple-relay scenarios. Further, SER is obtained for selective relaying systems, which is in quite simple and generalized form. It´s indicated that although selection among relays achieves the same diversity gain as the conventional all-participate schemes, it results in significant coding gain improvements. Simulation results verify the tightness of presented analysis at medium to high SNR regions in Nakagami-m environments with arbitrary severity parameter m ges 0.5.