Patent ID: 8644362

Claim:
A covert communication system comprising: a transmitter for sending a covert signal, the transmitter comprising: a modulator to modulate a data signal entering the transmitter to create a transmitter modulated signal, a first transmitter multiplying device coupled to the modulator to multiply the transmitter modulated signal with a chaotic signal to create a chaotic modulated signal, a transmitter chaos generator coupled to the first multiplying device to generate the chaotic signal, wherein the chaotic modulated signal reenters the transmitter chaos generator; a transmitter pseudo-random noise sequence generator to generate a transmitter pseudo-random noise sequence, and a second transmitter multiplying device coupled to the first multiplying device and to the transmitter pseudo-random noise sequence generator to multiply the chaotic modulated signal with the transmitter pseudo-random noise sequence to create the covert signal; and a receiver for receiving the covert signal, wherein the receiver comprises: a receiver pseudo-random noise sequence generator to generate a receiver pseudo-random noise sequence identical to the transmitter pseudo-random noise sequence, a first receiver multiplying device coupled to the receiver pseudo-random noise sequence generator to multiply the covert signal with the pseudo-random noise sequence to create a de-spread signal, a receiver chaos generator coupled to the first receiver multiplying device to generate a receiver chaotic signal, wherein the receiver chaos generator is of similar configuration as the transmitter chaos generator and wherein the de-spread signal enters the receiver chaos generator, a complex conjugate device coupled to the receiver chaos generator to complex conjugate the receiver chaotic signal to generate a conjugated signal, a second receiver multiplying device coupled to the first receiver multiplying device and the complex conjugate device to multiply the conjugated signal to the de-spread signal to create a receiver modulated signal, and a demodulator coupled to the second receiver multiplying device to demodulate the receiver modulated signal to generate a received data signal approximating the data signal entering the transmitter.