Security‐reliability tradeoff analysis of joint relay‐user pair and friendly jammer selection for physical layer security against multiple eavesdroppers

Abstract

This paper examines a wireless communication network comprised of a source and multiple relay‐user pairs in face of multiple malicious eavesdroppers. In order to improve the physical layer security of cooperative communication networks, a joint relay‐user pair and friendly jammer selection (JRUPaFJS) scheme is proposed. Apart from the impacts of friendly jammers on the eavesdroppers, that on the legitimate users is also taken into account due to the presence of channel state information estimation errors. The traditional round‐robin (TRR) scheme and traditional pure relay‐user pair selection (TPRUPS) scheme are considered as benchmark schemes. The exact closed‐form expressions of outage probability and intercept probability for the TRR and TPRUPS schemes as well as JRUPaFJS scheme over Rayleigh fading channels are derived. It is verified that the proposed JRUPaFJS scheme outperforms both the TRR and TPRUPS schemes in terms of their SRT, which demonstrates the wireless security and reliability benefits of exploiting JRUPaFJS scheme. Moreover, as the number of relay‐user pairs increases, the SRT of the TPRUPS and JRUPaFJS schemes improve notably, while as the number of eavesdroppers increases, the SRT of all the three schemes become worse.