Another closed-form expression of average error rate for the Nth best relay selection AF relaying over Rayleigh fading channels

Abstract

In this paper, we derive another approximated closed-form average error rate as a more tractable form for the Nth best opportunistic amplify-and-forward (OAF) relay systems over Rayleigh fading channels. At first, we derive the Nth best relay's selection probability. Based on this, the average symbol error rate (ASER) using the moment generating function (MGF) is derived as the approximated form. In particular, the closed-form expression for error probability is derived using the probability density function (PDF)-approach. In addition, it is verified that the derived analytical one can be a more tractable form having the specified the number of multiple summations and the specified length of each summation. Simulation results are finally presented to validate derived numerical ones.