Cooperative selection diversity with a single fixed gain amplify-and-forward relay in Nakagami-m fading channels

We present new exact closed-form expressions for the symbol error rate (SER) of cooperative selection diversity (CSD) with a single fixed gain amplify-and-forward (AF) relay. We consider the general fading condition of independent but not necessarily identically distributed (i.n.d.) Nakagami-m fading. We also present a closed-form expression for i.n.d. Rayleigh fading as a special case. We highlight the performance improvements provided by CSD with fixed gain relaying in unbalanced fading conditions. Numerical results substantiate the validity of our analysis.