Mainlobe Coherent Interference Suppression Method Based on Weighted Spatial Smoothing and Eigen-Projection Matrix Preprocessing

When array radar faces the coherent interference situation, the received expected signal will be erroneously cancelled. Especially when the coherent interference approaches the expected signal and becomes mainlobe coherent interference, the performance of adaptive beamforming method will degrade seriously. In order to solve these problems, a method based on weighted spatial smoothing and eigen-projection matrix preprocessing is proposed to suppress the mainlobe coherent interference in this paper. Firstly, the coherent interference is decorrelated with the expected signal by the weighted spatial smoothing algorithm, then the mainlobe interference is eliminated by the eigen-projection matrix preprocessing matrix. Finally, the effect of covariance matrix mismatch is reduced by diagonal loading. Simulation results demonstrate the effectiveness and robustness of the proposed algorithm.