提取混沌中谐波信号的时频方法  

Time-frequency method for harmonic signals extraction in chaos

作　　者：王国光[1] 王树勋[1] 何丽桥[2] 

机构地区：[1]吉林大学通信工程学院,长春130022 [2]吉林大学物理学院,长春130022

出　　处：《吉林大学学报（工学版）》2006年第6期963-966,共4页Journal of Jilin University:Engineering and Technology Edition

基　　金：国家自然科学基金资助项目(60172032)

摘　　要：首先采用谐波小波变换将观测信号分解成窄带信号,然后使用经验模态分解方法将每一个窄带信号分解为有限个内禀模态函数(IMFs),根据功率谱密度选取内禀模态函数,提取谐波信号。该方法的性能可由噪声缩减因子和相关系数两个指标度量。理论分析和仿真实验表明,在信噪比不太低的情况下,该方法对提取淹没在混沌和噪声背景下的谐波信号非常有效。A combination method of empirical mode decomposition （EMD） and harmonic wavelet transformation were used for harmonic signals extraction in chaos. Harmonic wavelet transformation to decompose the observed signal into several narrow band signals was conducted first. Then each narrow band signal was decomposed into a number of intrinsic mode function components （IMFs） which was selected according to power spectrum dense, and the harmonic signal was extracted. Performance of the method was evaluated by both a noise reduction factor and correlation between the extracted signal and the original noisefree signal. Theoretical analysis and computer simulation show that this method is effective in extracting harmonic signals provided that signal to noise ratio is not very low.

关 键 词：信息处理技术 信号提取 经验模态分解 谐波小波 混沌 

分 类 号：TP912.34[自动化与计算机技术]