Secrecy Performance of Amplify-and-Forward Relay Networks with Relay Selection under Nakagami-m Fading

In this paper, we examine the secrecy outage performance of a dual-hop relay network under Nakagami-m fading. Here, we consider a three-terminal wireless communication system, where one node (source) communicates to the other node (destination) via a group of relay nodes. Due to severe fading and heavy shadowing, the direct link between two communicating nodes is not suitable to achieve the desired performance. Therefore, one relay is opportunistically selected amongst K relay nodes to establish their communications. For providing relay cooperation, the best relay is selected based on criteria that maximize the secrecy outage performance. Selected relay applies amplify-and-forward operation to facilitate relay assistance by broadcasting the received signal. Along with the destination node, an eavesdropper also receives the broadcasted signals. For this setup, we derive the closed-form expressions of secrecy outage probability with the assumption that wireless channels experience Nakagami-m fading. Various numerical results are illustrated to highlight the key performance impact of different system and channel parameters. We also verify the accuracy of our derived expressions by comparing the results with similar work done in the literature.