Robust broadband beamforming algorithms using efficient realisation method

It is well known that adaptive beamformers can suffer significant performance degradation when the array response vector for the desired signal is not known exactly. Diagonal loading of the correlation matrix is a popular technique applied to the minimum variance/minimum power distortionless response beamformer to increase robustness of the array system. This paper presents two robust beamforming algorithms using efficient realisation techniques. The techniques do not use a pre-steered array and allow an array designer to specify the frequency response of the processor in the look direction and steered the main beam of specified frequency response in an arbitrary direction. The proposed techniques are computationally efficient. The techniques used in the paper extend a previously published technique used for narrow band beamforming to broadband beamforming. Simulation results exhibit enhanced robustness performance of the processor.