Optimization of LPI-FDA-MIMO Radar and MIMO Communication for Spectrum Coexistence

This letter studies the spectral efficiency of a multiple-input multiple-output (MIMO) radar with frequency diverse array (FDA) and a MIMO communication system in the same frequency band. To suppress mutual interference for both systems, and enhance low probability of intercept (LPI) capability of radar system, we propose a joint design of the transmit waveform and receive filter of radar, and the code-book employed by the communication system to form its space-time code matrix. Our problem formulation is to maximize the signal-to-interference-plus-noise ratio (SINR) and simultaneously minimize the probability of target detection of the radar signal under the peak-to-average ratio and communication rate constraints. Since the design problem is non-convex, we first transform it into three sub-optimization problems. An iterative algorithm is then developed to solve these subproblems to obtain the solution of the original problem. Simulation results show that the devised approach can effectively reduce the mutual interference as well as increase the SINR and LPI for radar system.