phase modulation

Phase modulation (PM) is a form of modulation that represents information as variations in the instantaneous phase of a carrier wave.Unlike its more popular counterpart, frequency modulation (FM), PM is not very widely used (except perhaps in the inappropriately named FM synthesis for musical instruments, introduced by Yamaha around 1982.) This is because it tends to require more complex receiving hardware and there can be ambiguity problems with determining whether, for example, the signal has 0° phase or 180° phase.
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Noun
1. modulation of the phase of the carrier wave
(synonym) PM
(hypernym) modulation

Angle modulation in which the phase angle of a carrier is caused to depart from its reference value by an amount proportional to the instantaneous value of the modulating signal. (188 )

B: (Fisika) modulasi fase
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Eng: phase modulation
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