Improved Blind Beamforming for Multipath Signals in Complex Interference Environment

In this paper, a new blind beamforming approach for multipath signals is proposed in complex interference environment where both strong and mild interferences exist. First, the spatial spectrum technique is applied to reconstruct the covariance matrix for the mild interferences. Subsequently the covariance matrix of the strong interferences is estimated via the dominant eigenvectors of the sample covariance matrix. The estimation of the composite steering vector (CSV) of desired multipath signals can be obtained as the principle eigenvector of the sample covariance matrix with interferences and noise components removed. Finally, the optimal beamformer is obtained with the estimated CSV and reconstructed interference-plus-noise covariance (INC) matrix. Simulation verified that the proposed blind beamforming approach outperforms existing representative approaches in terms of the overall performance in complex interference environment where both strong and mild interferences are existing.