Iterative regularization method in generalized inverse beamforming

Beamforming based on microphone array is a method to identify sound sources. It can visualize the sound field of the source plane and reveal interesting acoustic information. Generalized inverse beamforming (GIB) is one important branch of beamforming techniques due to its high identification accuracy and computational efficiency. However, in real testing situation, errors caused by measurement noise and configuration problems may seriously reduce the beamforming accuracy. As an inverse problem, the stability of GIB can be improved with regularization methods. We proposed a new iterative regularization method for GIB by iteratively redefining the form of regularization matrix and calculating the corresponding solution. Moreover, the new method is applied to functional beamforming and double-layer antenna beamforming respectively. Numerical simulations and experiments are implemented. The results show that the proposed regularization method leads to more robust beamforming output and higher accuracy in both the two applications. (C) 2017 Elsevier Ltd. All rights reserved.