Wireless security in selection decode-and-forward relay networks

In this paper, a confidential communication scenario is considered through selection decode-and-forward cooperative relay networks over Rayleigh fading channel in which a source communicates with a destination via multiple relays. A best relay is selected using selection combining technique which communicates with the destination. An eavesdropper observes their communication and tries to decode confidential information. In this situation, an interest is given to ensure secure communication between the best relay and the destination so that eavesdropper is unable to decode any information from the main channel (i.e. channel between relay and destination). The performance of the proposed model is analyzed based on the closed-form analytical expressions of the ergodic secrecy capacity and the secure outage probability taking into account the distances of relays from the source, destination and the eavesdropper. Analytical results show that the additional diversity provided by the best relay situated in a strategic location significantly improves the secure outage performance of the selection decode-and-forward relay networks.