FEATURELESS COVERT COMMUNICATIONS SYSTEM

A system and method of providing featureless covert communication is described. After synchronization is achieved between a covert transmitter and a covert receiver using two channels, one of which is a transmitted reference signal, a single channel is used to transmit the bulk of the communication message. The featureless covert communication system uses a digitally controlled noise source (capable of reproducing a pre-selected pseudo-random signal indistinguishable from ambient noise) at both transmitter and receiver. The digitally controlled noise source produces an uncorrupted reference signal at both locations. Since only once channel is used to transmit the message, 3 dB in power is saved. And, since the same reference signal is being generated locally at the receiver, corruption of the reference signal is eliminated, which improves the efficiency of the system by at least another 10 dB. The featureless covert communication system operates with signals that fall below the ambient noise levels and thus, even if intercepted, these signals should be confused with the normal occurrences of noise bursts in environment. Transmission of the two channel reference subsystem is limited to a very short duration which further minimizes interceptability of the system. To further complicate interception during the initial synchronization period, a controlled time delay may be inserted in one channel of the transmitter and a compensating time delay inserted in the other channel of the receiver.