Minimax optimization approach to sidelobe suppression filter design

A sidelobe suppression filter is designed to operate simultaneously with a matched filter. For the purpose of the design, a filter is canonically decomposed into two orthogonal components. One is the conventional matched filter, the other is the sidelobe suppression filter. The minimax optimization technique is utilized to determine the optimal filter weights to minimize the peak sidelobe level of the combined filter output. The technique is also applied to design a close-in sidelobe-free filter. The sidelobe performance of the proposed filter is compared with those of the MMSE inverse filter and the matched filter. The loss in processing gain compared with a matched filter and the filtering complexity are also examined.