利用小波变换对MEMS矢量水听器信号处理

Using wavelet transform for signal processing of MEMS vector hydrophone

为解决对水上未知目标的定位估计,充分利用接收信号,提出一种基于小波变换与傅里叶变换相结合的信号处理方法。采用中北大学研制的十字梁结构的MEMS矢量水听器接收声源信号,通过后续电路把声压信号转换成电压信号。先进行窄带滤波,保存有用信号频带;然后选择合适的小波阈值及小波基对信号进行小波降噪处理,减少低频噪声干扰,提高输出信噪比,为后续的信号处理及水声定位提供便利;最后基于MUSIC算法,结合直方图法进行目标方位估计,仿真结果表明,这种方法将定位精度提高到3°。

In order to solve the position estimation of unknown targets on the water and make full use of the received signals,a signal processing method based on wavelet transform and Fourier transform is proposed.The MEMS vector hydrophone,developed by North University of China,is used to receive the sound source signal,and the sound pressure signal is converted into the voltage signal by the follow-up circuit.And then select the appropriate wavelet threshold and wavelet based on the wavelet denoising of the signal processing to reduce low-frequency noise interference and improve the output signal to noise ratio,for the subsequent signal processing and underwater acoustic location to facilitate; Finally,based on the MUSIC algorithm and the histogram method,the azimuth estimation is carried out.The simulation results show that this method improves the positioning accuracy to 3°.