LFM signal optimization time-fractional-frequency analysis: Principles, method and application

The classical time-frequency analysis method is not the optimal signal representation method for LFM signal, fractional Fourier transform (FRFT) can represent signal from any fractional domain between time domain and frequency domain. Inspired by this characteristic, an optimization time-fractional frequency (TFF) analysis method for LFM signal is built in this paper. First, a new simple fractional wavelet transform (FRWT) is proposed using generalized fractional convolution, which can provide joint time and fractional-frequency information of signal. Furthermore, an optimization TFF analysis method based on FRWT is established. It can provide a robust and high-resolution TFF representation for LFM signal, especially for multi-component LFM signal with close or intersecting components. Finally, the FRWT-based TFF analysis method is successfully applied to the parameter estimation of LFM signal. Experimental results show that the FRWT-based parameter estimation method is superior to some existing methods in terms of accuracy and noise robustness. (c) 2022 Elsevier Inc. All rights reserved.