论文标题
能量浓缩的小波变换，用于瞬态信号的时间频率分析
An Energy-concentrated Wavelet Transform for Time Frequency Analysis of Transient Signals
论文作者
论文摘要
瞬态信号通常由一系列具有多价时间依赖性瞬时频率（IF）的模式组成，这给信号处理技术的开发带来了挑战。幸运的是，该信号的组延迟（GD）可以很好地表示为频率的单个有价值函数。通过考虑频域信号模型，我们提出了一种称为小波变换（WT）基于时间复合的同步同步转换（WTSST）的后处理方法。我们提出的方法将二维GD操作员嵌入了同步式框架中，以产生具有高能量浓度的瞬态信号的时频表示（TFR），并允许检索整个信号的整体或部分。提供了WTSST的理论分析，包括分析GD候选精度和信号重建精度。此外，基于WTSST，通过引入逐步完善方案，提出了基于WT的时间复合的多合同Queezing Transform（WTMSST），这进一步改善了WTSST方法无法处理强频变频信号的缺点。仿真和实际信号分析表明，所提出的方法具有适当描述瞬态信号的特征的能力。
Transient signals are often composed of a series of modes that have multivalued time-dependent instantaneous frequency (IF), which brings challenges to the development of signal processing technology. Fortunately, the group delay (GD) of such signal can be well expressed as a single valued function of frequency. By considering the frequency-domain signal model, we present a postprocessing method called wavelet transform (WT)-based time-reassigned synchrosqueezing transform (WTSST). Our proposed method embeds a two-dimensional GD operator into a synchrosqueezing framework to generate a time-frequency representation (TFR) of transient signal with high energy concentration and allows to retrieve the whole or part of the signal. The theoretical analyses of the WTSST are provided, including the analysis of GD candidate accuracy and signal reconstruction accuracy. Moreover, based on WTSST, the WT-based time-reassigned multisynchrosqueezing transform (WTMSST) is proposed by introducing a stepwise refinement scheme, which further improves the drawback that the WTSST method is unable to deal with strong frequency-varying signal. Simulation and real signal analysis illustrate that the proposed methods have the capacity to appropriately describe the features of transient signals.
