Outage Probability of Selection Cooperation With MRC in Nakagami- $m$ Fading Channels

Selection cooperation has been shown to be an effective way to implement cooperative diversity in wireless networks. In this letter, we investigate the outage performance of decode-and-forward selection cooperation with optimal maximal ratio combining (MRC) receiver at the destination to combine the signal replicas available from the source and the selected relay in Nakagami-/mbim fading channels with arbitrary real-valued/mbim. In particular, an exact closed-form expression for the outage probability is derived for integer values of fading severity parameter/mbim and an infinite summation expression for the noninteger situation. Our analysis extends previous results pertaining to selection combining (SC) receiver at the destination. Simulation and numerical results are presented to show the validity of the analytical results, as well as the effect of the two hops unbalanced fading conditions on the performance gain of MRC with respect to SC.