Some Researches On Estimation Of Instantaneous Frequency Of Signal

Instantaneous frequency (IF) is one of the important characteristics of express the physical substance of non-stationary signals. It has been widely used in the technical field of mobile communication, radar, sonar, etc. Therefore, instantaneous frequency estimation method study has important theoretical and practical value.First, we introduce the history of the study of instantaneous frequency of signal. There are many ways to estimate the instantaneous frequency in the history of the instantaneous frequency. In this paper we focus on the estimation of the signal instantaneous frequency, based on Hilbert transform, Wigner-Ville distribution and empirical mode decomposition. We analyze the advantages and disadvantages of estimation method based on the Hilbert transform. The structure of periodic analytic signals with positive instantaneous frequency was studied. This method for mono-component signal is very effective, but for multi-component signal will lose its efficacy. In order to analyze the multi-component signal, we try to use empirical mode decomposition to decompose the multi-component signal into several intrinsic mode functions(i.e., mono-component signals).Then analyze for each mono-component signal, so as to achieve the entire signal analysis. However, the empirical mode decomposition method for some signals is invalid. So, what are the characteristics for this kind of signals? This question is also a focus of our discussion in this paper.