Improved algorithm of mainlobe interference suppression based on eigen-subspace

When there is only the mainlobe interference signal, the algorithm of mainlobe interference suppression based on eigen-projection matrix preprocessing (EMP) has stronger robustness than that based on blocking matrix preprocessing (BMP). However, when the mainlobe interference signal and sidelobe interference signal are simultaneously present and the mainlobe interference signal's power is close to the sidelobe interference signal's power, the null steering direction's gain of sidelobe interference signal will be increasing. It decreases the performance of EMP algorithm. To solve these problems, an improved algorithm of the mainlobe interference suppression based on eigen-subspace is proposed to deal with the problem of the null steering reduction in the sidelobe interference in the case of high mainlobe interference-to-noise-ratio. Simulation results have shown that the proposed algorithm has good robustness which can effectively suppress the mainlobe interference and maintain the deep null steering in the direction of sidelobe interference signal in the array pattern, in the case of the different mainlobe interference-to-noise-ratio.