Joint antenna selection and beamforming for frequency diverse multiple-input multiple-output radar in mainlobe spectrum interferences and signal-dependent interferences coexistence scenarios

Due to the controllable degrees of freedom of frequency diverse array in the distance dimension, the frequency diverse multiple-input multiple-output (FDA-MIMO) radar can easily deal with mainlobe interference, which is often difficult to solve in traditional phased arrays. Nevertheless, the performance of FDA-MIMO radar will suffer from degradation in the scenario where spectrum interferences and signal-dependent interferences coexist. In order to solve this problem, a novel FDA-MIMO radar framework via antenna switching is proposed. Based on this framework, an effective method for jointly optimising antenna selection and beamforming against spectrum interferences and signal-dependent interferences is developed. The resulting optimization problem is nonconvex and NP-hard owing to the integer constraints caused by antenna selection. By relaxing the integer constraints, the original problem can be transformed into a convex optimization form and an iterative reweighting strategy is used to force the obtained solution to satisfy the integer constraints. Simulation examples show that the proposed algorithm has better performance in output signal-to-interference-plus-noise ratio (SINR) and beampattern radiation performance than the existing competitive methods. The performance of FDA-MIMO radar will suffer from degradation in the scenario where spectrum interferences and signal-dependent interferences coexist. To solve this issue, an effective method is developed by optimising antenna selection and beamforming. Simulation examples show that the proposed algorithm has better performance in output signal-to-interference-plus-noise ratio (SINR) and beampattern radiation performance than the existing competitive methods.image