Time-frequency analysis of backscattered signals from diffuse radar targets

TDARMA Model Estimation Using the MLS and the TF Distribution

“…This method can be used in the modeling of a non-stationary signal by considering the signal as the output of an LTV system with a stationary white noise input (Astrom, 1971). A convenient way to solve equation (5) for ak(n) and bk(n) is to replace the timedependent coefficients with their second-order expansion (Ding F. X., 2016), or an arbitrary order expansion (Kenny, 1993). However, in this paper we propose a method for estimating the timedependent parameters {ak(n)} and {bk(n)} from ζ(n,m) with less restrictions.…”

“…In this case, the representation of the signals and the characterization and design of the systems are conducted in either the time or the frequency domain (Haykin, 1991), (Huang, 1980), (Ding F. X., 2016). Whenever the signal of interest or the desired system operations are non-stationary, such approaches are quite limited, see for example (Kayhan, 1994), (Kenny, 1993), as they do not often express explicitly the signal or system non-stationarity. Whenever slow temporal variations are presumed, the problem is resolvable by partitioning the signal into time sections that are sufficiently small to be considered locally time-invariant and sufficiently long to yield the desired frequency resolution.…”