Study on the Problems in Extracting Instantaneous Characters of Signals Based on Hilbert Transform

With the help of the relationship between the real part and the imaginary part obtained from the analysis of the Hilbert transform, the instantaneous frequency, instantaneous phase and instantaneous amplitude of the signals at any moment can be defined. Therefore Hilbert transform is used in extracting instantaneous parameters of the signals. There are, however, some problems about the application of the Hilbert transform in practice. This paper deals with how to solve the problems,especially to extract the instantaneous frequency at high degree of accuracy .