WordNet (r) 3.0 (2006):

demodulation
    n 1: (electronics) the reception of a signal by extracting it
         from the carrier wave

The Free On-line Dictionary of Computing (30 December 2018):

demodulation
demodulate

    To recover the signal from the carrier.
   For example, in a radio broadcast using amplitude modulation
   the audio signal is transmitted as the mean amplitude of a
   radio-frequency carrier so demodulation requires a circuit
   which measures the amplitude and filters out the carrier.
   There are many other kinds of modulation and corresponding
   demodulation.

   (1998-07-29)