Secrecy Rate Maximization for a MISO-ISAC System with Multiple Eavesdropping Targets

This work investigates an integrated sensing and communication system with multiple eavesdropping targets and communication legitimate users. To ensure the security of transmitted information and sensing multiple eavesdropping targets, we strive to maximize the sum secrecy rate by designing transmit beamforming and artificial noise matrices under constraints on beampattern similarity and transmit power budget. We reformulate the underlying problem is reformulated into a quadratically constrained quadratic programming problem using a lower linearization approach and solve it via a semidefinite program approach to obtain the optimum solutions. Furthermore, a robust design is further proposed to counteract to the effects of inevitable channel imperfections of eavesdropping targets. Simulation results validate the effectiveness of the proposed design in secrecy transmission and target sensing, as well as the robustness against channel imperfection of eavesdropping targets.