Iterative reassignment: An energy-concentrated time-frequency analysis method

• Published in: Mechanical systems and signal processing Vol. 182; p. 109579
• Main Authors: Wei, Dahuan, Huang, Zhenfeng, Mao, Hanling, Li, Xinxin, Huang, Huade, Wang, Bang, Yi, Xiaoxu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2023
• Subjects: Fast varying signal; Harmonic-like signal; Impulsive-like signal; Iterative reassignment; Time-frequency analysis; Iterative reassignment; Time-frequency analysis; Harmonic-like signal; Impulsive-like signal; Fast varying signal
• ISSN: 0888-3270; 1096-1216
• DOI: 10.1016/j.ymssp.2022.109579

•We propose an energy-concentrated time-frequency analysis method that can not only deal with harmonic-like signals, but also characterize impulsive-like signals.•The proposed method can obtain ideal time-frequency analysis results when dealing with strong time-varying and strong frequency-varying signals.•The numerical and experimental examples are employed to validate the proposed method. Practical engineering signals usually show the characteristics of non-stationary and nonlinear, while time-frequency (TF) analysis is an effective means to deal with such signals. To accurately capture the transient features of fast varying signals, an iterative reassignment method is proposed. Firstly, the limitations of the synchrosqueezing transform (SST), time-reassigned synchrosqueezing transform (TSST), and the reassignment method (RM) in signal processing are discussed. Then, an iterative process is applied to the RM method, and the implementation process of the algorithm is introduced. Finally, several simulated signals and two sets of experimental data are employed to verify the effectiveness of the proposed method. The results show that the proposed method can not only deal with harmonic-like signals, but also characterize impulsive-like signals. By comparisons, it is shown that the proposed method has the better ability to extract transient features of strongly time-varying signals and strongly time-varying signals.