Noncircularity restoral eigenspace projection robust beamforming

A new robust beamformer exploiting noncircularity restoral of desired signal is proposed. The new approach is based on the eigenspace projection, further uses the noncircularity coefficient of the beamformer output to construct the cost function and modifies the pointing direction of the main beam via azimuth searching to maximize the noncircularity coefficient of the beamformer output, so that it could improve the output performance of beamformer while the robustness is guaranteed. The new method doesn't need to set user parameters, and it is applicable for the Qth (Q≥2) order noncircular modulated signal. At the same time, the new method is not sensitive to the noncircularity of the sidelobe interference signal, which is widely used in practice. At the end of this paper, the simulations for the case of second order noncircular signal and the case of high order noncircular signal were carried out, and the results verify the validity and superiority of the proposed approach.