Security-Reliability Tradeoff for Multiple Friendly Jammers Aided Relay Selection in Wireless Networks

In this paper, we consider a cooperative relay network consisting of a source, multiple intermediates, and a destination in the face of an eavesdropper. We propose a multiple friendly jammers (FJs) aided relay selection (MFJRS) scheme where an intermediate that maximizes the main channel capacity is chosen as the best relay, and the remaining intermediates act as FJs which can emit artificial noises to confuse the eavesdropper. We derive closed-form expressions of both outage and intercept probabilities and analyze the security-reliability tradeoff (SRT) performance for the MFJRS scheme. Numerical results show that the MFJRS scheme performs better than a conventional relay selection (CRS) and one FJ aided relay selection (OFJRS) schemes in terms of their SRT performance, indicating the effectiveness of multiple FJs in enhancing transmission security and reliability. It is also found that optimizing the power allocation factor between the best relay and multiple FJs further enhances the SRT performance.