Broadband Adaptive Beamforming Using UIA-MVDR Algorithm

Broadband adaptive beamforming is considered in this paper with a view to avoid the signal cancellation caused by signal-correlated interferences. The classic approach of spectral averaging is applied. However, the proposed approach, referred to as unitarily interpolated array minimum variance distortionless response (UIA-MVDR), is distinguished by imposing a unitary constraint on the transform matrix. It releases the restriction on the order of Bessel function expansion so that very accurate array manifold approximation can be achieved even in the case of small or middle arrays. Compared with many related approaches, UIA-MVDR destroys the correlation more completely and then achieves better performance. Its excellent performance is confirmed via a number of numerical examples.