一种基于加权TOPS的宽带DOA估计新方法  

New Direction-of-Arrival Estimation Method for Wideband Sources Using Weighted TOPS

作　　者：陈明建 胡振彪 陈林 Chen Mingjian;Hu Zhenbiao;Chen Lin(College of Electronical Engineering,National University of Defense Technology,Hefei,230037,China)

机构地区：[1]国防科技大学电子对抗学院

出　　处：《数据采集与处理》2019年第3期453-461,共9页Journal of Data Acquisition and Processing

基　　金：安徽省自然科学基金(1608085QF140)资助项目

摘　　要：针对投影子空间正交性测试(Test of orthogonality of projected subspaces,TOPS)对宽带信号波达方向估计(Direction of arrival,DOA)存在角度分辨率较低,且易出现伪峰的问题,提出了一种加权TOPS的宽带DOA估计新方法。该方法通过最大化各频率点信号子空间与噪声子空间特征值区分度选择参考频点,同时利用信号子空间投影代替其零空间投影;然后利用正交频率子空间测试法(Test oforthogonality of frequency subspaces,TOFS)对平方TOPS法的判定矩阵进行加权修正;最后对判定矩阵求迹实现宽带DOA估计,避免了奇异值分解。与现有的TOPS法、平方TOPS以及TOFS相比,该方法提高DOA估计精度,能够有效剔除伪峰,降低了算法复杂度,且对间隔相近信源DOA估计分辨率更高。仿真实验结果验证了该方法的有效性。Classical test of orthogonality of projected subspaces(TOPS)method is exposed to performance breakdown as the spurious peaks can largely appear in the pseudo spectrum.Here a new direction-of-arrival estimation method for wideband sources using weighted TOPS is introduced.First,it uses the single signal subspace of the reference frequency,where the difference between the smallest signal eigenvalue and the largest noise eigenvalue is the maximum.The proposed weighted TOPS uses the squared TOPS method and test of orthogonality of frequency subspaces(TOFS)method to improved DOA estimation performance,which can obtain the weighted matrix by suitable modification to extend the effectiveness of TOPS.Moreover,the weighted TOPS method uses signal subspace projection instead of null-space projection.Finally,direction-of-arrival estimation for wideband sources are estimated by using trace as performance metric instead of singular value decomposition in TOPS.Comparison of TOPS,squared TOPS and TOFS method,the proposed weighted TOPS can achieve reduction in spurious peaks,improve DOA estimation accuracy,and obtain better computational efficiency and resolution performance for closely spaced sources.Numerical simulations validate the effectiveness of the proposed method.

关 键 词：阵列信号处理 波达方向估计 宽带信号 正交投影子空间 

分 类 号：TN911.7[电子电信—通信与信息系统]