Near-Field Integrated Sensing and Communications Aided Covert Transmission

Near-field integrated sensing and communications (ISAC) is a key area of research for sixth-generation (6 G) networks. Compared to far-field ISAC systems, near-field effects enable more precise sensing and communication in both angle and distance domains. Taking advantage of this property, this paper proposes an optimization scheme for covert communication assisted by the near-field ISAC system. The proposed scheme jointly optimizes the communication beamforming matrix and the artificial noise (AN) covariance matrix to minimize the Cramer-Rao bound (CRB), while satisfying covert constraints and minimum communication rate constraints. To solve the optimization problem, we use the semidefinite relaxation (SDR) method to obtain the optimal solution. Numerical results demonstrate that the proposed scheme 1) effectively improves the sensing performance while ensuring communication performance and maintaining covert transmission, and 2) reveals a trade-off between CRB and covert rate.