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n. Abbr. pm or p-m
A method of signal transmission in which the phase of a carrier wave is varied to transmit information contained in the signal.
(Electronics) a type of modulation, used in communication systems, in which the phase of a radio carrier wave is varied by an amount proportional to the instantaneous amplitude of the modulating signal
radio transmission in which the carrier wave is modulated by changing its phase to transmit the amplitude and pitch of the signal.