Enhancing Secrecy Performance of Full-Duplex Relaying Systems Using IRS and RSMA

This paper proposes a secure wireless system that integrates rate-splitting multiple access (RSMA), intelligent reflecting surfaces (IRS), and full-duplex relaying (FDR) to enhance secrecy performance against multiple colluding eavesdroppers. Closed-form expressions for the secrecy outage probabilities (SOPs) and average secrecy capacities (ASCs) of both common and private messages are derived. Comparative analysis with a baseline RSMA-FDR system (without IRS) demonstrates the benefits of IRS in improving secrecy. Numerical results reveal that RSMA-IRS-FDR achieves superior secrecy performance, with SOPs and ASCs strongly influenced by transmission power, particularly differing between message types. Moreover, the adverse effect of residual self-interference (RSI) is substantially mitigated in the IRS-aided system. The secrecy performance is further enhanced by increasing the number of IRS elements. The study also investigates the impact of key parameters such as power allocation, target secrecy rate, fading order, Wi-Fi frequency, and number of eavesdroppers, offering practical insights for secure RSMA-IRS-FDR system design.