RSMA-Enhanced Physical Layer Security for ISAC Systems

In this letter, we enhance the physical layer security (PLS) of integrated sensing and communication (ISAC) systems using rate-splitting multiple access (RSMA). To ensure specific security requirements, we formulate a joint optimization problem that involves the precoding matrix and the common rate. The goal is to maximize the communication-sensing weighted secure sum rate (SSR), thereby enhancing the overall system performance while maintaining security. To solve the non-convex optimization problem, we adopt the staged algorithm named successive convex approximation with penalty (SCA-P) algorithm. Simulation results show that the proposed scheme has better security performance than the state-of-the-art schemes.