Intelligent reflecting surface aided co-existing radar and communication system

This paper explores the potential of intelligent reflecting surfaces (IRS) as a solution for enhancing radar detection and communication data transmission in crowded areas, where co-existing radar and communication (CRC) systems face distinct channel impairments. The proposed approach involves jointly optimizing the phase shift matrix of the IRS and the beamforming of the radar and communication systems, with the objective of maximizing the signal-to-interference-plus-noise ratio (SINR), while adhering to user-specified SINR requirements, radar transmit power, and base station (BS) power. To tackle this complex optimization problem, we introduce a Constrained Concave-Convex Procedure (CCCP) based Bisection Search (CCCP-BI) iterative algorithm. This algorithm utilizes CCCP to obtain the beamformers of the radar and communication systems, followed by the iterative Bisection Search (BI) to derive a solution for the PSM. Considering the computational complexity of CCCP-BI, we also propose an alternative Semi-Definite Programming (SDP)-based Bisection Search (BI-SDP) algorithm. Extensive simulations demonstrate the effectiveness of the IRS in the (CRC) system. Furthermore, we conduct performance comparisons with other benchmarks, evaluating the impact of various parameters on the received SINR at the radar receiver.