Secure Resource Allocation for Integrated Sensing and Semantic Communication System

As a new paradigm of communication, semantic communication (SC) differs from traditional communication based on bit transmission by transmitting semantic information, which demonstrates enormous potential in improving communication performance and efficiency. To ensure the transmission security, this paper studies the secure resource allocation problem of integrated sensing and semantic communication (ISSC) system in the scenario of multiple eavesdroppers. Specifically, the concept of secure semantic rate (SSR) is first proposed to measure the reliability of user information acquisition, and then an optimization problem is formulated to maximize the secure semantic efficiency (SSE), which represents the ratio of SSR to transmission power. To solve this problem, the optimization problem is first transformed into two subproblems, i.e., beamforming optimization problem and semantic parameter optimization problem. For the beamforming optimization subproblem, this paper simplifies the objective function using the Dinkelbach algorithm with given semantic parameters and proposes an alternating algorithm through iteratively solving a series of convex subproblems. For the semantic parameter subproblem, the monotonic decreasing property of the objective function with respect to semantic parameter is revealed mathematically under a given beamforming vector. Finally, simulation results verify the theoretical analysis.