宽带独立信号和相干信号的DOA估计

当独立信号和相干信号共存时,传统四阶累积量方法无法估计出宽带相干信号的来波方向(DOA),针对这个问题提出了一种新方法。该方法首先通过离散傅里叶变换,将宽带阵列接收数据分解为若干个窄带信号,构造出各个窄带频率处的自相关矩阵,再通过MUSIC(Multiple Signal Classification)算法估计出各个窄带信号的DOA,将各个窄带信号的空间谱相加求平均,通过谱峰搜索得到宽带独立信号的DOA;然后分离出独立信号的信息,构造出一个只包含宽带相干信号信息的矩阵,最后通过稀疏重构的方法估计出相干信号的DOA。计算机仿真结果证明该算法的正确性和有效性。

DOA Estimation for Wideband Independent and Coherent Signals

The traditional fourth-order cumulant（FOC）method can not estimate the DOA of coherent wideband signals when independent and coherent wideband sources coexist.For solving this problem,a novel method is introduced.Firstly,in the proposed method,wideband array data is broken into several narrow-band sources through discrete Fourier transformation（DFT）,then individual covariance matrix at each fre-quency is formulated.The DOA of individual narrowband sources is estimated by multiple signal classifica-tion（MUSIC）algorithm.All the spatial spectrum at each frequency are added up and the average spatial spectrum of all frequency is calculated.Then the DOA estimation of independent signals can be obtained by searching the spatial spectrum.Secondly,a matrix that only contains the information of coherent signals can be formulated by eliminating the contribution of independent sources.Finally,the DOA estimation of coher-ent sources can be obtained by using spare reconstruction method.The results of computer simulations dem-onstrate the correctness and effectiveness of the proposed method.