University of Auckland/Department of Physics/Physics 102/Modulation
Modulation is the process of shifting the periodic message waveform and varying its properties into a carrier frequency suitable for transmission. Common modulation types include AM (Amplitude modulation) and FM (Frequency modulation). In amplitude modulation, the received information is determined by the amplitude of the modulating signal, while in frequency modulation the frequency of the modulating signal is the governing factor. FM modulation is used in long distance transmission as the carrier is less sensitive to noise and barriers in the channel.