窗口伸缩优化的同步压缩算法及其在变转速工况瞬时频率估计上的应用

针对传统时频分析方法的固定窗在分析非线性调频信号时存在时频聚集性不高等问题,在短时傅里叶变换基础上引入同步压缩理论,利用信号的局部信息特征,提出一种窗口伸缩优化的时频同步压缩变换算法,并在此基础上推导出二阶及高阶的窗口伸缩优化的同步压缩变换算法.该方法能够兼顾同步压缩变换和重排的优势,进一步锐化时频脊线,从而增强时频表...

Synchrosqueezing Algorithm for Window Extension and Compression Optimization and Its Applications in Instantaneous Frequency Estimation under Variable Speed Conditions

The fixed window of traditional time-frequency analysis method had the problems of low time-frequency aggregation when analyzing nonlinear frequency modulation signals.The synchrosqueezing theory was introduced on the basis of short-time Fourier transform, and a time-frequency synchrosqueezing transform algorithm for window scaling optimization was proposed by using the local information characteristics of the signals, and the second-order and high-order synchrosqueezing transform algorithms for window scaling optimization were deduced. This method might take into account the advantages of synchrosqueezing transform and reassignment method, and further sharpen the time-frequency ridges, thereby enhancing the energy concentration level of the time-frequency representation and improving the signal time-frequency resolution. In view of the unknown prior knowledge of the signals, the minimum information entropy criterion was used to optimize the window width of the intercepted signals, and the entropy values were used to estimate the time-varying window parameters to determine the optimal window parameters at each moment. The effectiveness of the method was verified through the analysis of the simulated signals and the actual signals.