Weighted Subspace-Constrained Adaptive Beamforming for Sidelobe Control

A weighted subspace-constrained minimum variance distortion-less response (WS-MVDR) beamformer is proposed for robustly controlling the peak sidelobe level (PSL) as well as the sidelobe shape of adaptive array pattern with stable mainlobe. The adaptive weight vector is projected onto the subspace constructed from the weighted sidelobe steering vectors. The norm of the projection is constrained below the derived constant value determined by the desired PSL. The only inequality constraint is introduced to the conventional MVDR beamformer, resulting in a second-order cone programming problem. The numerical results demonstrate that WS-MVDR outperforms existing ones in terms of beampattern control capability and computational complexity.