Outage probability of amplify-and-forward underlay cognitive relay networks with selection diversity over Nakagami-m fading channels

In this paper, the outage performance is investigated for cognitive dual-hop relay networks with amplify-and-forward (AF) relay and selection combining (SC) receiver at the destination under spectrum sharing constraints on primary user (PU) over independent and identically distributed (i.i.d.) Nakagami-m fading channels. We derive an exact closed-form expression for the outage probability (OP) of the considered system under the peak interference power I_p at the primary user, and the impact of the PU location on the OP performance is studied also. Moreover; the effects fading severity for the two hops on the OP is investigated also for this cognitive relay network (CRN).