声矢量传感器阵宽带相干信号子空间最优波束形成
Coherent signal subspace wideband optimal beamforming for acoustic vector-sensor array
-
摘要: 提出了基于矢量传感器阵的宽带相干信号子空间最优波束形成。建立了矢量传感器阵的宽带阵列信号模型,将宽带聚焦思想引入到了矢量传感器阵宽带处理,证明了矢量传感器阵与声压传感器阵宽带聚焦矩阵之间的关系,为矢量传感器阵宽带聚焦矩阵的构造提供了一种方法。推导了基于矢量传感器阵宽带最优波束形成的空间谱,通过空间重采样方法实现矢量传感器阵宽带聚焦,避免了对目标源方位的预估。通过仿真验证了矢量传感器阵具有更优越的性能:可以解宽带相干源;能够实现全空间无模糊定向;可以空间欠采样,因而在不增加计算量的基础上,能够提高阵列处理的性能;克服了传统声压传感器线阵端射方向上,目标方位估计性能下降的缺点。Abstract: 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.