Coherent signal subspace wideband optimal beamforming for acoustic vector-sensor array

This paper presents a method of coherent signal subspace based wideband optimal beamforming for acoustic vector-sensor (AVS) array. The wideband array signal model for AVS array is presented, and the wideband focusing is firstly introduced into wideband processing for AVS array. The relationship between focusing matrixes for AVS array and acoustic pressure-sensor array is derived, thus it provides a method for the construction of wideband focusing matrixes for AVS array. The spatial spectrum of the optimal beamforming for the AVS array is derived, the wideband focusing for AVS array data in this paper is achieved by spatially resampling technology without preliminary estimates or a priori knowledge of the spatial distribution of the sources. The simulation results demonstrate that the proposed beamformer for AVS array has several advantageous performance, it can: (1) resolve coherent wideband source problems; (2) realize unambiguous direction finding in the whole space; (3) allow the uniform interelement spacing to exceed the Nyquist half-wavelength upper limit; and (4) overcome the shortcoming of poor performance when dealing with direction estimation of endfire sources.