宽带DOA估计的频域时延补偿算法

DOA Estimation Algorithm for Wideband Signals Using Delay Compensation Method in Frequency Domain

针对宽带波达方向(Direction of Arrival,DOA)估计中导向矢量的频率不一致问题,提出一种新算法.首先对搜索方向信号进行时延补偿,使其与法线方向信号具有相同的阵列时延特征,同时将其它方向信号当作噪声处理,然后计算子空间的正交性并将其作为该搜索方向上空间谱值,最后给出快速算法以降低运算量.由于滤波器的群时延值不能任意改变,采用频域方法实现时延补偿.新算法不需要预估信号源数目和DOA初值,且仿真结果表明:在信号源互不相关和功率谱密度分布平坦的前提下,新算法分辨率更高、估计误差更小.

To settle the variability of steering vector with frequency in direction of arrival（ DOA） estimation for wideband signals,a newalgorithm is proposed. First,the array delays of the signal in search direction are compensated to have the same characteristics as that in normal direction. Meanwhile,the signals in other directions are processed as noise.Then,the value of spatial spectrum in search direction is measured by the computed orthogonality of subspaces. Finally,to improve the computational efficiency,a fast algorithm is used in the newalgorithm. Because the delay of filter can not be changed arbitrarily,a frequency domain method is adopted to compensate the array delays with compensation matrix. The newalgorithm doesn＇t require the number of sources or the initial values of DOAs. More than this,the results of simulation experiments showthat it performs better than existing algorithms in terms of the resolution and the estimation error when the received signals are incoherent and their power spectral distributions are smooth.