Pulse-position modulation
FORM OF SIGNAL MODULATION IN WHICH THE MESSAGE IS ENCODED BY TRANSMITTING A SINGLE PULSE IN ONE OF VARIOUS POSSIBLE TIME SHIFTS
Pulse position modulation
Pulse-position modulation (PPM) is a form of signal modulation in which M message bits are encoded by transmitting a single pulse in one of 2^M possible required time shifts. This is repeated every T seconds, such that the transmitted bit rate is M/T bits per second.