Joint Source-Relay Selection for Improving Wireless Physical-Layer Security

We explore the physical-layer security for a multi-source multi-relay wireless network in the presence of an eavesdropper, in which one of multiple sources is scheduled to send its message to a destination with the assistance of multiple decode-and-forward (DF) relays. One eavesdropper is considered at the receiver side, and assumed to be capable of overhearing the transmission from relays to destination. In this paper, the round-robin scheduling and the joint source-relay selection schemes are presented to improve the physical-layer security of the multi-source multi-relay system, and their closed-form intercept probability expressions are derived over Rayleigh fading channels. Numerical results demonstrate that the proposed joint source-relay selection scheme achieves a better performance than the traditional round-robin scheduling in terms of the intercept probability.