Covert Transmission Aided Secure MU-MIMO ISAC Systems

This paper deals with the security problem of covert transmission in integrated sensing and communication (ISAC) systems, which aims to probe a target while simultaneously transmitting confidential signals to a covert communication user in the presence of multiple public communication users. Specifically, the target angular location is unknown and random, and among the public users, there is a warden hostile to the covert user. To realize covert transmission and target localization, we propose a covert beamforming strategy by maximizing the covert rate subject to public communication quality-of-service, transmission covertness, direction-of-angle (DoA) estimation, and power constraints. To tackle the formulated non-convex design problem, we devise a covert beamforming algorithm based on the alternating direction method of multipliers. Simulation results verify the effectiveness and feasibility of the proposed ISAC design in transmission security and DoA estimation.