Joint Radar-Communication Beamforming Considering Both Transceiver Hardware Impairments and Imperfect CSI

This paper studies multi-user multi-input multi-output (MU-MIMO) beamforming designs under different channel uncertainties for integrated sensing and communication (ISAC) system with hardware impairments. The Cramér-Rao Bound (CRB) of radar sensing is minimized by considering the energy and the signal-to-noise-plus-interference ratio (SINR) requirements of Internet of Things Devices (IoTDs). Specifically, we first reformulate the CRB by using the Schur complement theorem. To handle the non-convex constraints, we employ the S-procedure and the Bernstein-type inequality for approximation. Subsequently, we adopt the Gaussian randomization algorithm to seek the rank-one optimums. Numerical results indicate that the proposed transmission designs are more robust in the presence of both hardware impairments and imperfect CSI.