基于窄带处理的多线谱中心频率提取方法  

A Method to Extract Center Frequency of Multiline Spectrum Based on Narrowband Feature

作　　者：方宇晨 于化鹏 贺钦源 白利兵 FANG Yuchen;YU Huapeng;HE Qinyuan;BAI Libing(School of Automation Engineering,University of Electronic Science and Technology of China,Chengdu 611731,China;National Innovation Institute of Defense Technology,Academy of Military Science,Beijing 100071,China)

机构地区：[1]电子科技大学自动化工程学院,成都611731 [2]军事科学院国防科技创新研究院,北京100071

出　　处：《无人系统技术》2023年第4期61-68,共8页Unmanned Systems Technology

摘　　要：针对水下运动平台辐射噪声存在多根线谱时,现有中心频率提取方法计算量较大的问题,提出一种基于窄带处理的多线谱中心频率提取方法。在水下目标辐射噪声特性分析的基础上,根据能量判据得到信号线谱所在频段,进而利用小波阈值降噪处理原始信号,结合线谱特征特性,在降噪后信号频域上分别寻得存在线谱的各个频段,将包含线谱的频段视为窄带内的正弦波信号,采用正弦波信号频率估计方法,分别提取出线谱的中心频率。实验结果表明,该方法可以准确获得全部线谱的中心频率,提取值与实际值的最大偏差不超过0.4 Hz。相比传统方法,该方法计算量较小,为多根线谱的中心频率估计问题提供了一种便捷的解决方案,具有一定的工程应用价值。When the underwater moving platform radiated noise has multiple line spectra,most of the existing center frequency extraction methods need to obtain the instantaneous frequency of the line spectrum,resulting in a large amount of calculation.In order to solve this problem,on the basis of the characteristics of underwater target radiation noise,the frequency band of the signal line spectrum is obtained according to the energy criterion,and then process the original signal by wavelet threshold noise reduction.Combined with the characteristic characteristics of the line spectrum,each frequency band with the line spectrum in the frequency domain of the signal after noise reduction is found respectively.The frequency band containing the line spectrum is regarded as the sine wave signal in the narrow band.And the sine wave signal frequency estimation method is used to extract the center frequency of the line spectrum respectively.The experimental results show that the algorithm can accurately obtain the center frequency of all line spectra,and the maximum deviation between the extracted value and the actual value does not exceed 0.4 Hz.Besides,the algorithm requires less calculation compared with the traditional algorithm.The estimation problem provides a convenient solution and has certain engineering application value.

关 键 词：水声信号处理 小波阈值降噪 多普勒频移 频率估计 线谱 中心频率提取 

分 类 号：TB566[交通运输工程—水声工程]