低复杂度的MIMO声呐协方差矩阵重构方法  

A low complexity covariance matrix reconstruction method of MIMO sonar

作　　者：程雪 王英民[1,2] CHENG Xue;WANG Yingmin(School of Marine Science and Technology,Northwestern Polytechnical University,Xi’an 710072,China;Key Laboratory of Ocean Acoustics and Sensing Northwestern Polytechnical University,Ministry of Industry and Information Technology,Xi’an 710072,China)

机构地区：[1]西北工业大学航海学院,西安710072 [2]西北工业大学,海洋声学信息感知工业和信息化部重点实验室,西安710072

出　　处：《应用声学》2019年第4期666-673,共8页Journal of Applied Acoustics

基　　金：国家自然科学基金项目(51879221)

摘　　要：多输入多输出声呐在对目标进行测向时会产生复杂的运算量,从而降低算法的测向效率。针对这一问题,提出了一种基于降维变换方法的低复杂度协方差矩阵重构方法。该方法能够抑制噪声,提高目标测向性能。首先利用降维变换方法对接收信号进行波束形成,获得降维的协方差矩阵,再对矩阵进行Toeplitz处理,抑制矩阵的相干性。所得到的新的协方差矩阵,通过特征分解获得噪声子空间和信号子空间,利用 MUSIC方法进行测向。为了进一步降低运算复杂度,利用阵型所满足的旋转不变性,可以采用ESPRIT算法对目标进行波达方向估计。理论分析和实验结果表明,该方法有效降低了运算复杂度,提高了算法的测向性能。在有限快拍数的情况下,与传统测向方法相比,具有运算速度快、目标分辨力强的特点。Multiple-input multiple-output (MIMO) sonar will generate complex operation when it is used to estimate the direction of targets, which will lead to the reduction of algorithm efficiency. To solve this problem, a low complexity covariance matrix reconstruction method based on dimension reduction transformation is proposed. This method can help to suppress noise and improve direction finding performance. Firstly, by using the dimension reduction transformation method to form the echo signals, we can obtain a low dimensional covariance matrix. Then, by employing Toeplitz processing of the matrix to suppress coherence, we can achieve the noise subspace and signal subspace by characterizing new covariance matrix. MUSIC algorithm can be used to estimate the direction of targets. In order to further reduce the computational complexity, we can adopt the ESPRIT algorithm to estimate the direction of arrival (DOA) by utilizing the rotation invariance satisfied by the MIMO array. Both theoretical analysis results and numerical simulation results verify that this algorithm effectively reduces the computational complexity, and improves the direction finding performance. In the condition of limited snapshots, compared with the traditional direction finding methods, it has the characteristics of fast calculation speed and strong target resolution.

关 键 词：MIMO声呐 低复杂度 降维变换 TOEPLITZ 

分 类 号：O427.9[理学—声学]