To allow for sophisticated signal processing algorithms in the receiver of a localization system that operates according to the multilateration principle, it is valuable to know the shape of signal transitions. However, if comb filters are used during digital signal processing and the effective sampling rate is increased by virtual oversampling, then frequency offsets of the modulation signal’s harmonics will alter such transitions. In this paper it is shown, that this effect can be modeled by an effective low-pass filter function in continuous-time domain.