瞬时频率 Resources

Showing items tagged with "瞬时频率"

Application Background: Empirical Mode Decomposition (EMD) decomposes signals into monocomponent signals called Intrinsic Mode Functions (IMFs), enabling instantaneous frequency calculation through Hilbert transform. The primary challenge in practical Hilbert-Huang transform applications is the endpoint effect. Our solution introduces an adaptive spurious IMF filtering algorithm using residue-to-original-signal correlation coefficient as threshold. Key Technology: Complex signal decomposition into monocomponent signals requires each IMF to satisfy two conditions: (1) Extremum and zero-crossing counts must be equal or differ by one throughout the data length; (2) The mean of upper and lower envelopes must be zero at any point. The implementation involves adaptive sifting with envelope interpolation and statistical boundary handling.

MATLAB 330 views Tagged

Research on time-frequency characteristics of time series including Fourier transform and inverse transform, fast Mellin transform and inverse transform, short-time discrete Fourier transform for instantaneous frequency extraction. Implementation of time-frequency distributions: Born-Jordan distribution, Butterworth distribution, and Choi-Williams distribution for visualizing instantaneous frequency patterns.

MATLAB 227 views Tagged