In connection with a frequency modulated (FM) communications system, exemplary aspects concern processing a desired channel of a frequency modulated (FM) signal based on an indication of an amplitude-level difference between a measured amplitude of a desired channel in the FM broadcast signal and a measured amplitude of another (possibly-interfering) channel. Based on such amplitude-level difference indication, an approach is selected for estimating the frequency spectrum of the other (possibly-interfering) channel in the FM broadcast signal. The selected approach may differ depending on whether the amplitude-level difference corresponds to an amplitude-level difference for which a frequency spectrum of the desired channel may be determined via a coarse estimate or via a less-coarse estimate of the frequency spectrum of the other channel.