Another method of conveying information is by means of pulses of voltage
    or current .

    With pulse modulation the carrier wave is not sinusoidal, but consits of repeated
    rectangular pulses. The amplitude, width or position of the pulses can be altered
    by the information signal, as illustrated in Fig. 10

    Pulse amplitude modulation is that form of  modulation in which the duration of
    a pulse is varied in accordance with some characteristic of the modulating
    signal. Sometimes pulse width modulation is called pulse duration modulation or
    pulse length modulation .

    Pulse position modulation is that form of modulation in which the positions
    in time of the pulses are varied in accordance with some characteristic of the
    modulating signal without a modification of pulse width.
 
 

 

INDEX

HOME