Abstract: 1. A binary digital communication system comprising a transmitter and receiver: said transmitter comprising means for alternately radiating in response to the digits of a binary message two signals of non-periodic energy which have been delayed by a predetermined amount with respect to one another, and means for phase shifting one of said signals by 180.degree. prior to radiation thereof in response to one of the "0" and "1" digits of the binary message; said receiver comprising means for receiving the signals alternately radiated by said transmitter, means for delaying the alternately received signals with respect to one another so they are brought back into correlation, and correlation-sensitive means to which the correlated received signals are fed, the output of said correlation-sensitive means being representative of said binary message.

Abstract: 5. An intelligence communication system comprising a transmitter and a receiver; said transmitter comprising means for obtaining a relatively wide band random energy carrier signal, means for modulating said random carrier signal with an intelligence signal thereby forming a message signal, means responsive to said wide band energy obtaining means for deriving a reference signal which differs in frequency with said message signal by a definite fixed amount and means for radiating to the receiverr both the message and reference random signals; said receiver comprising an antenna for picking up both the message and reference random signal simultaneously, means for operating on at least one of said message and reference random signals to obtain message and reference random signals which are recombined and mixer means for multiplying the recombined message and reference random signals to obtain a resultant signal from which the intelligence signal can be derived.