基于谱熵的自适应广义S变换时频滤波器设计
|
摘要
将信息熵引入到广义S变换时频滤波中,提出一种基于谱熵的自适应广义S变换时频滤波器设计方法。计算信号广义S变换的时频谱,将时频谱各时间点的频率区间划分成若干个小区间,计算各区间时频谱熵,以时频谱熵最大区间的时频谱的平均值作为阈值,以此来衡量信号的杂乱程度。若该时间点上的时频谱值大于阈值,则将该点时频谱值清零。采用广义S逆变换进行重构。该方法可自适应地调节时频滤波因子,有效滤除干扰信息。
In time-frequency filter design based on S transform,the time-frequency filtering area can be selected by the Exp,and the basic wavelet of S transform is fixed.To solve these problems,the concept of information entropy theory was introduced into the generalized S transform time-frequency filtering,and an adaptive generalized S transform time-frequency filter design method based on the spectral entropy was proposed.While calculating the signal's time-frequency spectrum by generalized S transform,the time-frequency spectrum's frequency range at each time point can be divided into some small zones;and while calculating the interval spectral entropy,the mean value of time-frequency spectrum in the spectral entropy maxima interval can be taken as the threshold to measure signal's disorder degree.The spectrum value at this time point can be cleared while it's greater than threshold.The de-noised signals can be reconstructed by generalized S inverse transform.This method can be adaptive to adjust time-frequency filtering factor and effectively remove interference information.Applying this method and a conventional filtering method to simulating the signal processing can verify the validity of this method.
In time-frequency filter design based on S transform,the time-frequency filtering area can be selected by the Exp,and the basic wavelet of S transform is fixed.To solve these problems,the concept of information entropy theory was introduced into the generalized S transform time-frequency filtering,and an adaptive generalized S transform time-frequency filter design method based on the spectral entropy was proposed.While calculating the signal's time-frequency spectrum by generalized S transform,the time-frequency spectrum's frequency range at each time point can be divided into some small zones;and while calculating the interval spectral entropy,the mean value of time-frequency spectrum in the spectral entropy maxima interval can be taken as the threshold to measure signal's disorder degree.The spectrum value at this time point can be cleared while it's greater than threshold.The de-noised signals can be reconstructed by generalized S inverse transform.This method can be adaptive to adjust time-frequency filtering factor and effectively remove interference information.Applying this method and a conventional filtering method to simulating the signal processing can verify the validity of this method.
引文
[1]Stockwell R G,Mansinha L,Lowe R P.Localization of theComplex Spectrum:the S Transform[J].IEEE Transac-tions on Signal Processing,1996,44(4):998～1001.
[2]Theophanis S,Queen J.Color Display of the LocalizedSpectrum[J].Geophysics,2000,65(4):1330～1340.
[3]Pinnegar C R,Mansinha L.The S-transform with Win-dows of Arbitrary and Varying Shape[J].Geophysics,2003,68(1):381～385.
[4]Mansinha L,Stockwell R G,Lowe R P.Pattern Analy-sis with Two Dimensional Spectral Localization:App li-cation of Two-dimensional S-transform[J].Physica,1997,239(3):286～295.
[5]Mcfaden P D,Cook J G,Forster L M.Decompositionof Gear Vibration Signals by the Generalized S-trans-form[J].Mechanical Systems and Signal Process,1999,13(4):691～707.
[6]高静怀,陈文超,李幼铭,等.广义S变换与薄互层地震响应分析[J].地球物理学报,2003,46(4):526～532.
[7]陈学华,贺振华.改进的S变换及在地震信号处理中的应用[J].数据采集与处理,2005,20(4):449～453.
[8]张荣标,胡海燕,冯友兵.基于小波熵的微弱信号检测方法研究[J].仪器仪表学报,2007,28(11):2078～2083.
[9]蔡涵鹏,贺振华,黄德济,等.基于时频谱熵的储层分布检测[J].石油天然气学报,2010,32(2):66～68.
[2]Theophanis S,Queen J.Color Display of the LocalizedSpectrum[J].Geophysics,2000,65(4):1330～1340.
[3]Pinnegar C R,Mansinha L.The S-transform with Win-dows of Arbitrary and Varying Shape[J].Geophysics,2003,68(1):381～385.
[4]Mansinha L,Stockwell R G,Lowe R P.Pattern Analy-sis with Two Dimensional Spectral Localization:App li-cation of Two-dimensional S-transform[J].Physica,1997,239(3):286～295.
[5]Mcfaden P D,Cook J G,Forster L M.Decompositionof Gear Vibration Signals by the Generalized S-trans-form[J].Mechanical Systems and Signal Process,1999,13(4):691～707.
[6]高静怀,陈文超,李幼铭,等.广义S变换与薄互层地震响应分析[J].地球物理学报,2003,46(4):526～532.
[7]陈学华,贺振华.改进的S变换及在地震信号处理中的应用[J].数据采集与处理,2005,20(4):449～453.
[8]张荣标,胡海燕,冯友兵.基于小波熵的微弱信号检测方法研究[J].仪器仪表学报,2007,28(11):2078～2083.
[9]蔡涵鹏,贺振华,黄德济,等.基于时频谱熵的储层分布检测[J].石油天然气学报,2010,32(2):66～68.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心