基于调频Z变换的均匀线阵波达方向估计

An Algorithm for Wideband Direction of Arrival Estimation Based on Chirped Z Transform

提出了一种基于调频Z变换(CZT)的宽带波达方向估计算法.由均匀线阵的理想聚焦条件,提出了其聚焦矩阵的波矢量域求解原理及计算方法:首先从聚焦频率处的聚焦矩阵中依次选取一行向量,用CZT分别计算其它子带内,各聚焦矩阵中相应位置的行向量的波矢量谱,再由傅立叶反变换得到相应的行向量.该方法可选择信号频带范围内的任意值作为聚焦频率,不需要方位预估,且能获得较好的渐进无偏估计性能.计算机仿真和水池试验结果验证了理论分析的正确性.

An algorithm for wideband direction of arrival（DOA） estimation based on chirped Z transform（CZT） is proposed.According to the ideally focusing condition of uniform linear array（ULA）,an idea in the wave vector space to solve focusing matrices and the corresponding solution are presented：A row vector in the focusing matrix at the focusing frequency is chosen,as for the focusing matrix of an arbitrary sub-band,the spectrum of the row vector at same position is calculated with CZT,and all vectors are obtained by inverse fast Fourier transform（IFFT）.With this method,any value within the signal frequency range can be chosen as the focusing frequency,and good asymptotic unbiased performance can be acquired without any pre-estimated DOA.The validity of these conclusions is validated with computer simulations and pool experiments.