An electromagnetic or audio SIGNAL, one or more of whose PARAMETERs is modulated by another signal. See: MODULATION.
In radio transmission, the carrier wave is in a broadcast frequency band (kilohertz or megahertz range) and the modulating signal is in the AUDIO range. Upon receiving the MODULATED CARRIER, a DEMODULATION process retrieves the modulating signal which is the broadcast signal. See: RADIO SPECTRUM.
See also: AMPLITUDE MODULATION, FREQUENCY MODULATION, HETERODYNE, SIDEBAND.