摘要
提出一种WVD(Wigner Ville distribution)的改进方法。应用离散余弦谐波小波变换对多分量信号进行分解,计算分解后得到的单分量信号的WVD,将单分量信号的WVD沿频率轴串联得到整个信号的WVD,抑制分布的交叉项。应用修改群延时函数减少因WVD核函数截断而产生的波动效应,改善分布的时频分辨率。通过算例中的线性调频信号和应用实例中轴承振动信号验证表明,改进后的WVD有满意的时频分辨率和明显的交叉项抑制能力,能够通过离散余弦变换实现其快速算法,算法快速、简单,适合非平稳工程信号的时频分析。
A new method was proposed for improving the performance of the Wigner Ville distribution.The WVDs of the subbands gotten by DCHWT（discrete cosine harmonic wavelet transform）,was concatenated to obtain an overall WVD,significantly free from the existence of cross-terms was applied to reduce the Gibbs effect from the truncation of the Wigner Ville distribution kernel.Examples of application demonstrated that this proposed method obeys the desirable properties of timefrequency resolution and strikingly reduces cross-terms.This method can realize the simple and fast algorithm through DCT discrete cosine transform and is suitable for joint time-frequency analysis of non-stationary engineering signal.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2010年第2期198-202,共5页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家"973"重点基础研究发展计划资助项目(2007CB714706)
