改进维纳滤波器及其在目标方位估计中的应用

针对复杂的水声环境以及信噪比较低的目标信号导致方位估计性能较差的问题,本文提出了一种基于改进维纳滤波器和波束形成器的方位估计方法,该方法能够抑制噪声,提高目标方位估计性能。首先利用改进维纳滤波器抑制各通道接收数据中的噪声,提高输出信噪比。在此基础上,将改进维纳滤波器的输出通过波束形成器,获得目标的方位估计。改进维纳滤波器能够通过调整滤波器参数,控制滤波器的噪声抑制能力和信号失真。因此,针对不同的波束形成器对信号失真的敏感程度不同,可以通过调节改进维纳滤波器的参数,获得噪声抑制与信号失真之间的最佳折中,从而提高输出信噪比,降低目标方位估计的信噪比门限和均方根误差。仿真和实验结果验证了本文方法。 

Modified wiener filter for direction of arrival estimation

When the underwater environment is complicated and the Signal-to-Noise Ratio (SNR) is low, the performance of the Direction Of Arrival (DOA) estimation is poor. To tackle this problem, we propose a spatial-temporal filter based on the modified Wiener filter and the beamforming method to reduce the received noise and estimate the DOA in the low SNR environments. First, the received data is processed by the modified Wiener filter. As a result, the noise is reduced in the time domain. Second, the output data of the modified Wiener filter is processed by the beamforming method. As a consequence, the noise is reduced in the spatial domain. Furthermore, we can obtain the best performance of the DOA estimation by adjusting the modified Wiener filter parameter. The simulation and experimental results show that the output SNR is increased and the Root-Mean-Square Error (RMSE) of the DOA estimation is decreased.