基于插值圓阵的宽带信号二维空间谱估计

在阵列信号处理中,确定信号的波达方向(DOA)需要估计信号的二维(2-D)空间谱。C。Usha Padmini等人(1994)已证明,圆阵用于估计宽带信号的DOA时具有许多好的特性。尤其是在基于圆阵的宽带信号子空间一维DOA估计中,即使不用延迟抽头也不会出现频率-方向模糊。在估计宽带信号的2-D空间谱时,我们发现用不带延迟抽头的圆阵会出现频率-仰角模糊。本文提出了一种用插值圆阵估计宽带信号2-D空间谱的新方法。在估计中,采用大孔径的圆阵(rmin/2)能获得更好的分辨性能和估计稳健性。

TWO-DIMENSIONAL SPATIAL-SPECTRUM ESTIMATION FOR WIDE-BAND SOURCES BASED ON INTERPOLATED CIRCULAR ARRAYS

In array signal processing, 2-D spatial-spectrum estimation is required to determine DOA of multiple signals. A circular array of sensors is found to possess several nice properties for DOA estimation of wide-band sources. C. Usha Padmini et al. (1994) have suggested that there is no frequency-direction ambiguity in azimuth estimation for wide-band signals by using a circular array, even without the use of any tap delay elements. In 2-D spatial-spectrum estimation for wide-band signals, we find that it is impossible to avoid the ambiguity in source frequency-elevation angle pairs using a circular array. In this paper, interpolated circular arrays are used to perform 2-D spatial-spectrum estimation for wide-band sources. In the estimation, a large aperture circular array (r min/2) is found to possess suprior resolution capability and robustness.