Directional Gain Based Noise Covariance Matrix Estimation for MVDR Beamforming

This paper is devoted to the problem of noise covariance matrix (NCM) estimation. It proposes a time-frequency masking based approach. We first present an optimal mask function based on the mean-squared error criterion. To estimate this mask, we employ the recently developed directional gain method based on the knowledge of the signal incident angle. To demonstrate the effectiveness of the proposed NCM estimator, we integrate it into the minimum variance distortionless response (MVDR) beamformer. The speech enhancement results in noise-plus-interference environments show the advantages of the proposed method over two baseline beamforming algorithms.