Hu Yang, Liu Yimin, Wang Xiqin
Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
Sensors (Basel). 2017 Mar 25;17(4):682. doi: 10.3390/s17040682.
This paper considers the problem of direction-of-arrival (DOA) estimation of coherent signals on passive coprime arrays, where we resort to the fourth-order cumulants of the received signal to explore more information. A fourth-order cumulant matrix (FCM) is introduced for the coprime array. The special structure of the FCM is combined with the array configuration to resolve the coherent signals. Since each sparse array of a coprime array is uniform, a series of overlapping identical subarrays can be extracted. Using this property, we propose a generalized spatial smoothing scheme applied to the FCM. From the smoothed FCM, the DOAs of both the coherent and independent signals can be successfully estimated on the pseudo-spectrum generated by the fourth-order MUSIC algorithm. To overcome the problem of occasional false peaks appearing on the pseudo-spectrum, we use a supplementary sparse array whose inter-sensor spacing is coprime to that of either existing sparse array. From the combined spectrum aided by the supplementary sensors, the false peaks are removed while the true peaks remain. The effectiveness of the proposed methods is demonstrated by simulation examples.
本文考虑了无源互质阵列上相干信号的波达方向（DOA）估计问题，在此我们借助接收信号的四阶累积量来挖掘更多信息。为互质阵列引入了一个四阶累积量矩阵（FCM）。将FCM的特殊结构与阵列配置相结合来分辨相干信号。由于互质阵列的每个稀疏阵列都是均匀的，所以可以提取出一系列重叠的相同子阵列。利用这一特性，我们提出了一种应用于FCM的广义空间平滑方案。从平滑后的FCM中，可以在由四阶MUSIC算法生成的伪谱上成功估计出相干信号和独立信号的DOA。为了克服伪谱上偶尔出现虚假峰值的问题，我们使用一个辅助稀疏阵列，其传感器间距与现有任何一个稀疏阵列的传感器间距互质。从由辅助传感器辅助的组合谱中，虚假峰值被去除而真实峰值得以保留。仿真示例证明了所提方法的有效性。
