Methods and systems for processing signals are provided and may include removing a DC component from a signal envelope comprising a combined signal within a range of allocated FM channels to generate a modified signal envelope. Fluctuation in power in the signal envelope may be detected based on a ratio of a magnitude of the signal envelope and a magnitude of the modified signal envelope. The removing may further include low-pass filtering the signal envelope to generate a low-pass filtered signal envelope. A square values of the low-pass filtered signal envelope may be determined to generate a squared signal envelope. The squared signal envelope may be high-pass filtered to generate a high-pass filtered signal envelope. The fluctuation in power in the signal envelope may be detected based on a ratio of a magnitude of the high-pass filtered signal envelope and a magnitude of the low-pass filtered signal envelope.