Pulse Radio Communication

a communications system in which continuous messages are transmitted by means of short-duration (pulsed) radio signals. In such systems periodic trains of rectangular pulses are used as primary data carriers. Four main types of pulse modulation can be produced by changing the parameters of the pulses. Pulse code modulation, which is produced by quantization of the original signal, is also widely used in pulse radio communication.

Pulse radio communication systems have high noise immunity. Multichannel communication using time-division multiplexing increase is also based on pulse radio communication. Time-division multiplexing is possible because, with a high off-on time ratio of the pulses (the ratio of the repetition period to the duration of the pulse), large time intervals exist between pulses; other pulse trains may be placed in the intervals. For example, in a two-channel transmission of two different messages, the modulated pulse trains of the first and second channels are added. As a result, a multimode signal is produced. It is then used to modulate the high-frequency oscillations of a transmitter that is radiating a radio signal through an antenna. In the receiver of a pulse radio communication system, the radio signal is detected and converted into a multimode signal, which is converted (by means of channel separation apparatus) into the initial form—that is, individual signals belonging to one or another channel of the pulse radio communication system. Multichannel pulse radio communication is widely used in various communications systems (including those using artificial earth satellites), in telemetry, and in remote control.