A.Shafieezadeh - Granduate Student
M.Motavalli - Assistant professor

This paper describes four methods for extracting the instantaneous frequency of a given signal. These four algorithms ate short time Fourier transform, wavelet transform, empirical mode decomposition and Hilbert transform, and generalized pencil of function methods. A SDOF structure is modeled and subjected to a varying, superimposed amplitude and frequency- modulated excitation. The structural response is analyzed by these methods and its instantaneous frequency is estimated and shown in the paper.

Instantaneous frequency ,STFT , wavelet transform , EMD-HT, GPOF