Analysis method of nonstationary waveform based on modulation model

This paper describes a new analysis method for nonstationary signals from the viewpoint of a waveform based on a modulation model. In this model, an instantaneous phase angle is considered to consist of two kinds of time-dependent parameters. The first is a smoothly rotating component and the second is a rapidly variable component. These two parameters enable us to analyze precise variations of nonstationary waveforms. This analysis method is confirmed by numerical evaluations.