关键词: 小波变换, Morlet小波, 小波相干, 相位差估计

Abstract: Accurate estimation of phase delay between two signals is very important. The Fourier transform method is suitable for deterministic signals. However, it is hard to distinguish or identify signals’ transient changes. The wavelet method allows to capture the time and frequency varying features of signals. It also has the obvious advantages in analyzing non-stationary signals. The coherency wavelet transform using Morlet wavelet is proposed to estimate the phase delay of two signals. The estimation performances are studied at different conditions. The simulation results show that the wavelet-based method can accurately estimate the phase delay at low SNR. In comparison with DTFT, the advantage of wavelet-based method is validated. This method can also be used to estimate the phase delay between two non-stationary signals.

Key words: wavelet transform, Morlet, wavelet coherency, phase delay estimator