Robust widely linear beamforming based on spatial spectrum of noncircularity coefficient

•We propose a robust widely linear (WL) beamforming algorithm for receiving noncircular signals.•The spatial spectrum of noncircularity coefficient is firstly defined in the context of the optimal WL MVDR beamformer.•The conjugated interference-plus-noise covariance matrix is reconstructed.•The extended steering vector is corrected by using the augmented interference-plus-noise covariance matrix.

In this communication a robust widely linear (WL) beamforming algorithm for the reception of a noncircular signal is proposed. The spatial spectrum of noncircular coefficient is firstly introduced in the context of the optimal WL minimum variance distortionless response beamformer. The augmented interference-plus-noise covariance matrix is reconstructed instead of the augmented sample covariance matrix. The proposed algorithm not only outperforms the conventional robust adaptive beamforming techniques, but also has a better performance against the model mismatch than the previous robust WL beamforming algorithms. Numerical simulations verify the effectiveness of the proposed algorithm.