Enhancing Reliability and Security in AF Relay-Assisted RSMA with Cooperative Jamming

Abstract

This paper investigates the reliability and security performance of an amplify-and-forward (AF) relay-assisted rate-splitting multiple access (RSMA) system with cooperative jamming. In the considered model, a single-antenna relay assists the transmission from a source to multiple legitimate users while simultaneously injecting artificial jamming to degrade the reception capability of a passive eavesdropper. Moreover, closed-form analytical expressions for the outage probability (OP) of the legitimate users and the intercept probability (IP) at the eavesdropper are derived under Rayleigh fading channels. Furthermore, to gain deeper insights into the system behavior, asymptotic expressions of the OP and IP are obtained in the high signal-to-noise ratio (SNR) regime, which reveal the impact of key system parameters and the achievable diversity order. Numerical results validate the accuracy of the analytical derivations. In addition, the results demonstrate that the proposed AF relay-assisted RSMA scheme effectively enhances reliability while limiting the interception capability of the eavesdropper through appropriate power allocation and cooperative jamming design.