低快拍下混合信号DOA快速估计算法  

Fast estimation algorithm for DOA of mixed signal in low snapshots

作　　者：姚震 杨闯 纪晓东 YAO Zhen;YANG Chuang;JI Xiaodong(State Key Laboratory of Network and Switching Technology,Beijing University of Posts and Telecommunications,Beijing 100876,China)

机构地区：[1]北京邮电大学网络与交换技术国家重点实验室,北京100876

出　　处：《系统工程与电子技术》2024年第2期722-728,共7页Systems Engineering and Electronics

基　　金：国家自然科学基金(62101059,61925101);北京市自然科学基金(L223007)资助课题。

摘　　要：实时定位移动设备在电子对抗系统中至关重要,其性能主要取决于波达角(direction of arrival,DOA)的估计速度。低快拍是快速DOA估计的先决条件。目前基于稀疏重构算法的DOA估计具有适应低快拍的优势,但估计精度受限于初始观测矩阵,且估计速度受限于观测矩阵高维度的多次迭代。为此,提出一种空间差分矩阵和稀疏重构耦合的低快拍下高精度快速估计算法。首先利用空间差分矩阵消除非相干信号和噪声对相干信号估计结果的影响,提升初始观测矩阵的准确度;然后对完备字典做前后空间平滑处理,克服高维度信号处理复杂难题,实现快速估计;最后分别估计非相干信号和相干信号。仿真验证结果表明,相比稀疏重构方法,所提方案初值敏感度显著降低,在保障精度相当甚至小幅度提升的前提下,运行时间复杂度降低50%以上。Locating mobile devices in real time is crucial in electronic countermeasures systems,whose performance mainly depends on the estimated speed of the direction of arrival(DOA).Low snapshots are a prerequisite for fast DOA estimation.The current DOA estimation based on the sparse reconstruction algorithm has the advantage of adapting to low snapshots,but the estimation accuracy is limited by the initial observation matrix,and the estimation speed is limited by multiple iterations of the high-dimensional observation matrix.To this end,a fast estimation algorithm with high precision under low snapshots coupled with spatial difference matrix and sparse reconstruction is proposed.Firstly,the spatial difference matrix is used to eliminate the influence of incoherent signals and noise on the estimation results of coherent signals,and improve the accuracy of the initial observation matrix.Then,the complete dictionary is processed with spatial smoothing before and after,so as to overcome the complex problem of high-dimensional signal processing and realize fast estimation.Finally,the incoherent and coherent signals are estimated separately.The simulation verification result shows that compared with the sparse reconstruction method,the sensitivity of the initial value of the proposed scheme is significantly reduced,and the running time complexity is reduced by more than half under the premise that the accuracy is guaranteed to be equal or even slightly improved.

关 键 词：波达角估计 稀疏重构 空间差分 混合信号 空间平滑 

分 类 号：TN911.7[电子电信—通信与信息系统]