Wiktionary
n. any of a number of techniques whereby a series of information-carrying quantities occurring at discrete instances of time is encoded into a corresponding series of electromagnetic carrier pulses
WordNet
n. modulation that imposes a signal on a train of pulses
Usage examples of "pulse modulation".
Now if the caterpillar is endless tail on Earth, head on Centaurus III and we impose pulse modulation on those waves, we can get the message carried by the modulation there faster than the caterpillar himself would have gotten there.
Then I recognize the pulse modulation of the beam and accept it within my communications relays.
The answers turned out to be surprisingly simple: the molecular receivers would respond to a pulse modulation impressed on a low-intensity, radio-frequency field surrounding the body.