A Robust MVDR Spectrum Estimation Technique

A major problem in applying Minimum Variance Distortionless Response (MVDR) beamformer, also known as Capon beamformer, in operational systems is the potential sensitivity to mismatch between actual and assumed models for the array response and/or the received signals used to derive the beamformer. Typical mismatches that have been addressed are DOA mismatch, sensor gain and phase perturbation, and sensor position perturbation. The subject of mutual coupling, for the most part, has been ignored in the development of algorithms for robust beamforming. In this paper, we present an extension of a previously developed robust MVDR beamformer that takes into account the mutual coupling between elements of the antenna array and the uncertainties in the array response and in the mutual coupling explicitly. We present several experimental results using measurements that were carried out in an anechoic chamber.