In pulse modulation, the carrier wave is in the form of pulses. Mentioned below are the types of pulse modulation.
Pulse amplitude modulation (PAM) The amplitude of the pulse varies in accordance with the modulating signal.
Pulse width modulation (PWM) The pulse duration varies in accordance with the modulating signal.
Pulse position modulation (PPM) In PPM, the position of the pulses of the carrier wave train is varied in accordance with the instantaneous value of the modulating signal.