An Eigendecomposition-Based Approach to Blind Beamforming in a Multipath Environment

This letter devises a new approach to blind beamforming for multipath coherent signal reception. It is shown that in the scenarios where the interferences are moderately stronger than the signal, namely, the interference-to-signal ratio is mildly high, the composite steering vector (CSV) of multipath coherent signals can be estimated via the eigendecomposition of a reduced covariance matrix, which subtracts the components of interferences and noise from the array covariance matrix. The proposed eigendecomposition-based blind beamformer (EBB) is thereby obtained by substituting the estimate of CSV into the minimum variance distortionless response beamformer. It is also shown that the proposed EBB weight vector is actually equal to the principal eigenvector of the reduced covariance matrix. The performance of the proposed EBB is demonstrated by numerical simulations.