窄带细化Wigner-Ville分布分析的快速实现方法

Fast Realization of Zoom-spectrum Wigner-Ville Distribution Analysis in a Narrowband

水下目标辐射线谱噪声的多普勒信息可用于估计目标上的噪声源参数。由于噪声源的低频和低速特性,其多普勒频移变化微弱,需要在选定窄带内进行高分辨率时频分析。Wigner-Ville分布(WVD)具有良好的时频聚焦性能,但是当频率分辨率要求较高时,其计算量和存储空间长度也大幅增加。该文提出一种选带细化WVD的快速数值计算方法。该方法对线性调频Z变换(CZT)进行改进并与WVD相结合,可以大幅提高选定窄带内高分辨率WVD时频分析的计算效率。数值仿真和海试数据验证了方法的有效性。

Doppler information of line spectrum can be used to estimate the parameters of radiated noise sources on underwater target.Because of the low frequency and low speed characteristics,the Doppler frequency shift changes weakly.Its time-frequency analysis should be limited in a selected narrow-frequency bandwidth with high resolution.Wigner-Ville Distribution（WVD） has excellent time-frequency focusing property,but the amount of calculation and storage space are increased sharply with the higher calculation resolution demanding.A fast calculating method is proposed for selected bandwidth zoom WVD analysis.The method improves the Chirp-Z Transform（CZT） algorithms,and combines that with WVD,improves greatly calculation performance of high resolution zoom WVD analysis.Computer simulation and experimental result at sea demonstrate the validity of the presented method.