摘要
WVD(wigner-ville distribution)是一种常见的时频表示方法。为了消除WVD中出现的交叉项,提出了一种新的时频表示方法:线调频小波WVD(chirplet wigner-ville distribution,CWVD)。利用多分量的复杂信号可以通过频率旋转算子转换得到若干个单一频率的简单信号的特点,将WVD应用在频率旋转后的信号上,使用频移算子偏移信号的瞬时频率。由多项式函数或者样条函数逼近估计的IFs(instantaneous frequencies)来计算算子的参数。通过测试信号验证了多项式CWVD和样条CWVD的有效性。CWVD在抑制交叉项方面较其他时频方法具备更好的性能,且能量集中性能突出。
Wigner-Ville Distribution is a common time-frequency representation method.In order to eliminate the cross-term in WVD,a new method of time-frequency representation named Chirplet Wigner-Ville Distribution is proposed.The multi-component signal can be transformed into several simple mono-frequency signals by frequency rotating operators,and WVD is applied to the rotated signals,then frequency shift operators are utilized to relocate the signal’s IFs.The operators’parameters come from the estimation of the IFs which are approached with a polynomial functions or spline functions.The effectiveness of the polynomial CWVD and spline CWVD is verified by the test signal,and the excellent performance of CWVD is revealed by comparing with other time-frequency representation methods.
作者
王豪
董广明
陈进
赵发刚
WANG Hao;DONG Guangming;CHEN Jin;ZHAO Fagang(State Key Laboratory of Mechanical System and Vibration,Shanghai Jiao Tong University,Shanghai 200240,China;Shanghai Satellite Engineering Institute,Shanghai 200240,China)
出处
《北京信息科技大学学报(自然科学版)》
2020年第5期5-8,70,共5页
Journal of Beijing Information Science and Technology University
基金
国家重点研发计划资助项目(2019YFB2004600)
国家自然科学基金项目(51575339,51775330)。
关键词
时频表示
交叉项
WVD
多项式调频小波变换
样条调频小波变换
time-frequency representation
cross-term
Wigner-Ville distribution
polynomials chirplet transform
spline chirplet transform