AN Assisted Secure ISAC Beamforming: Countering Covert Eavesdropper

The current physical layer security designs in integrated sensing and communication (ISAC) system commonly rely on the prior information about the eavesdropper, such as location and channel state information (CSI). However, for the covert eavesdropper, the absence of prior information significantly degrades security performance. To deal with this issue, an artificial noise (AN)-assisted ISAC secure beamforming scheme is proposed to counter the covert eavesdropper while considering the fairness of uses’ achievable secrecy rate. This scheme is more robust because it does not require any prior information of eavesdropper. We formulate an optimization framework to jointly design transmitted precoding matrix and AN vector. This complex non-convex multi-proportional fractional programming is solved by the proposed algorithm framework based on quadratic transformation-successive convex approximation (QT-SCA). Simulation results demonstrate the effectiveness and robustness of the proposed scheme for countering the covert eavesdropper.