频域单快拍压缩感知目标方位估计和信号恢复方法
Direction of arrival estimation and signal recovery based on single snapshot compressed sensing in frequency domain
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摘要: 方位估计和信号恢复分别是水下目标定位、跟踪和目标识别的前提。提出了一种阵列频域单快拍压缩感知的水下目标方位估计和信号恢复方法。首先将阵列接收数据变换到频域,取频域单快拍数据作为压缩感知的测量值,然后根据频域快拍对应的频率、搜索方位和阵列流形构造过完备的阵列流形矩阵作为压缩感知的感知矩阵,最后通过基追踪算法估计搜索方位上目标信号和功率,实现DOA估计与信号恢复。宽带仿真实验数据验证结果表明,同等条件下完成同样的目标方位分辨,提出的方法比最小方差无失真响应方法要求的阵元数和快拍数较少,要求的信噪比更低,恢复的目标信号更加准确,波形相关系数达到89%以上。海上实验数据处理结果表明,目标检测能力优于最小方差无失真响应方法,证明该方法可以适用于实际声呐系统。Abstract: Direction of arrival (DOA) estimation and signal recovery is the base of the underwater target localization, tracking and recognition. Based on the compressed sensing theory, a method for DOA estimation and source signal recovery is proposed using the single snapshot processing of the array data in frequency domain. The array data are transformed to frequency domain, and the single snapshot frequency domain data are regarded as the measure data of the compressed sensing. According to the frequency, searching orientation and array manifold, the overcomplete array manifold is constructed as the sensing matrix of the compressed sensing. Both the target signal and power of the searching orientation are estimated by the basis pursuit method to complete DOA estimation and signal recovery. Simulation results show that the proposed method has a number of advantages over the minimum variance distortionless response (MVDR) method, including improved robustness to noise, less requirement in sensor number and snapshot number. And the correlation coefficient of the signal reaches up to 0.89. Experiment results in real environments verify that the proposed approach performs more effectively in the detection of weak targets than the MVDR method and can be applied to real sonar system.