LOW-COST ADAPTIVE MAXIMUM ENTROPY COVARIANCE MATRIX RECONSTRUCTION FOR ROBUST BEAMFORMING

Abstract

In this paper, we present a novel low-complexity adaptive beamforming technique using a conjugate gradient (CG) algorithm to avoid matrix inversions. The proposed method exploits algorithms based on the maximum entropy power spectrum (MEPS) to estimate the noise-plus-interference covariance matrix (MEPS-NPIC) so that the beamforming weights are updated adaptively, thus greatly reducing the computational complexity. MEPS is further used to reconstruct the desired signal covariance matrix and to improve the estimate of the desired signals's steering vector (SV). Simulations show the superiority of the proposed MEPS-NPIC approach over previously proposed beamformers.