Efficient processing of nonstationary signals requires time-varying approac
h. An interesting research area within this approach is time-varying filter
ing. Since there is a certain amount of freedom in the definition of time-v
arying spectra, several definitions and solutions for the time-varying filt
ering have been proposed so far. Here were will consider the Wigner distrib
ution based time-varying filtering form defined by using the Weyl correspon
dence. Its slight modification will be proposed and justified in the proces
sing of noisy frequency modulated signals based on a single signal realizat
ion. An algorithm for the efficient determination of the filters' region of
support in the time-frequency plane, in the case of noisy signals, will be
presented. In the second part of the paper, the theory is applied on the f
iltering of multicomponent noisy signals. The S-method is used as a tool fo
r the filters' region of support estimation in this case. This method, comb
ined with the presented algorithm, enables very efficient time-varying filt
ering of the multicomponent noisy signals based on a single realization of
the signal and noise. Theory is illustrated by examples.