demodulates the FM modulated signal Y at the carrier frequency Fc (Hz). Y and Fc have sample frequency Fs (Hz). FREQDEV is the frequency deviation (Hz) of the modulated signal.

uses the message signal X to modulate the carrier frequency Fc (Hz) and sample frequency Fs (Hz), where Fs > 2*Fc. FREQDEV (Hz) is the frequency deviation of the modulated signal.