Simulation and Identification of Nonstationary Systems Using Linear Time-Frequency Methods

Abstract

This work investigates synthesis and identification methods for nonstationary systems. Use of the time or frequency domains individually has limitations in many applications. Analysis in two domains jointly—that is, time frequency (TF)—gives us the potential to describe complex system behavior. A localized transfer function in time and frequency can describe time-variant filters. Operations between the TF expansion of an input signal and the two-dimensional transfer function of a system are equivalent to filtering in the TF plane. Simple analytic examples explain the basic methods and are applied to simulated and real data. Models of evolving systems are realized parametrically and nonparametrically in the TF domain.