Time-Frequency Domain Characterization of Stationary and Non stationary Signals?

This paper presents the various methods for the spectral analysis of signals for the stationary as well as non-stationary signals. Due to non-stationary characteristics of the signals, it has been always a challenge to achieve time frequency distribution of such signals. Between the various techniques of signal analysis, this paper uses Fourier transform, Short time Fourier transform, wavelet transform, and Hilbert Huang transform for the analysis of stationary as well as non-stationary signals. A comparison between these frequency transformation techniques has been made by analyzing four types of test signals. The result shows the best method for the analysis of each type of test signal.