A Robust LCMP Beamformer with Limited Snapshots

Abstract

This paper deals with the problem of automatic diagonal loading for the linear constrained minimum power beamformer. To find the beamformer’s weights, the linear constrained minimum power problem is reformulated into its generalized sidelobe canceller implementation, which is an unconstrained least-squares problem. To solve this problem, we utilize a bounded perturbation regularization approach where a perturbation matrix with a bounded norm is added to the linear transformation matrix of the least-squares problem in order to enhance the singular-value structure of the matrix. Compared to different diagonal loading methods, the proposed method shows superiority in performance when the number of snapshots is limited.