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.