Yueyi Dong

Tian Zhang, Zhirong Su, Yueyi Dong

Due to great efficiency improvement in resource and hardware space, integrated sensing and communication (ISAC) has gained much attention. In the paper, the physical layer security (PLS) of ISAC system under communication eavesdropper together with sensing eavesdropper is investigated. The system secrecy rate is maximized by transmit beamforming design of communication and sensing signals when taking sensing security, sensing performance and transmit power constraint into consideration. To deal with the formulated non-convex optimization problem, the successive convex approximation (SCA) together with the first-order Taylor expansion and semidefinite relaxation (SDR) is utilized. Additionally, it is theoretically validated that the SDR does not yield sub-optimality in the paper. Thereafter, an iterated joint secure beamforming algorithm against communication and sensing eavesdroppers is proposed. Simulation results validate the effectiveness and advance of the proposed scheme.

Yueyi Dong, Tian Zhang

In the paper, the physical-layer security for reconfigurable intelligent surface (RIS) aided integrated sensing and communication (ISAC) system is studied. There is an active eavesdropper (AE) as well as a passive eavesdropper (PE), and they cooperate each other. By joint base station beamforming and RIS reflection design, we aim to achieve the best secure data communications with guaranteed sensing performance. Mathematically, taking the constraints on sensing performance and transmission power in consideration, the system secrecy rate maximization problem is formulated with respect to transmit beamforming, RIS reflection, and receive beamforming. The formulated problem is non-convex and is decomposed to three subproblems by applying the alternating optimization (AO). For the decomposed subproblem, we utilize the quadratic penalty method and successive convex approximation (SCA) for the solution derivation. Thereafter, an iterative numerical algorithm, referred to as the joint beamforming and reflection design (JBRD) algorithm, is proposed. Finally, numerical results demonstrate the effectiveness and superiority of the proposed algorithm.