Secrecy Outage Performance of Cooperative Relay Network With Diversity Combining

In this paper, the secrecy outage probability of threshold-based decode-and-forward (DF) cooperative relay network is evaluated. Unlike other works to date, we assume combining of direct and relayed signals both at the destination and the eavesdropper. All the links undergo Rayleigh fading and the relay can perfectly decode the message, only if the received SNR meets a particular threshold. The secrecy performance is compared for the system with either selection combining (SC), or with maximal ratio combining (MRC) or with the combination of both, at the destination and eavesdropper. We have shown that the eavesdropper channel quality, required secrecy rate, pre-defined threshold and the choice of diversity scheme significantly affects the secrecy performance of the system.