Implementation of the Phase Difference Method Proposed by Wang Fenghua et al.

This implementation of the phase difference method proposed by Wang Fenghua et al. is primarily used in signal processing to extract the instantaneous frequency of signals. The fundamental principle of this method involves calculating the phase difference of the signal to obtain instantaneous frequency information. The phase difference method is suitable for single-component signals, meaning signals containing only one frequency component. In code implementation, this typically involves using the angle function to extract phase information from analytic signals (often obtained via Hilbert transform), followed by differentiation using the diff function to calculate instantaneous frequency as the rate of phase change. Another method that can be used to solve for instantaneous frequency employs the autocorrelation approach. The autocorrelation method performs correlation operations between the signal and its delayed version, thereby obtaining the instantaneous frequency characteristics of the signal. In algorithmic implementation, this can be achieved using the xcorr function to compute autocorrelation, with frequency information typically derived from the phase of the autocorrelation function or through peak detection in the frequency domain after Fourier transformation.