Delay-modulated random energy intelligence communication system

• US 4,324,002 A
• Filed: 03/18/1960
• Issued: 04/06/1982
• Est. Priority Date: 03/18/1960
• Status: Expired due to Term

• Current Assignee: Lockheed Martin Space Operations Company (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Space Operations Company (Martin Marietta Corporation)
• Inventors: Spilker, James J. Jr.
• Primary Examiner(s): Birmiel, Howard A.
• Application Number:
  US04/017,729
• Time in Patent Office: 8,054 Days
• Field of Search: 332/68, 332/9, 332/9 R, 252/6.4, 252/6.8, 252/6.6, 329/145, 329/104, 375/2.1, 375/23, 375/58, 455/26, 455/27, 455/29, 455/59, 455/101, 179/15.55 T
• US Class Current: 380/35
• CPC Class Codes: H04K 1/00 Secret communication

Abstract

1. An intelligence communication system comprising a transmitter and a receiver; said transmitter comprising non-periodic energy means for generating a carrier, means for effecting a change in the time or frequency domain of the carrier signal whereby a reference signal is generated, means for effecting a variable delay in said carrier signal in accordance with the intelligence to be communicated whereby a message signal is generated, and means for radiating the reference and message signals; said receiver comprising means for picking up the reference and message signals, means for effecting a change in the picked up signal which change is complementary with that caused by first said change effecting means, and means responsive to said picking up means and last said change effecting means for deriving the intelligence signal therefrom.

Claims

1. An intelligence communication system comprising a transmitter and a receiver;

said transmitter comprising non-periodic energy means for generating a carrier, means for effecting a change in the time or frequency domain of the carrier signal whereby a reference signal is generated, means for effecting a variable delay in said carrier signal in accordance with the intelligence to be communicated whereby a message signal is generated, and means for radiating the reference and message signals;

said receiver comprising means for picking up the reference and message signals, means for effecting a change in the picked up signal which change is complementary with that caused by first said change effecting means, and means responsive to said picking up means and last said change effecting means for deriving the intelligence signal therefrom.

2. The invention of claim 1 in which said carrier generating means comprises a source of wide band energy and means for passing a relatively large frequency band of the output of said source.

3. The invention of claim 2 in which first said change effecting means comprises means for delaying the carrier for a preselected time and last said change effecting means comprises means for delaying the picked up signal by the same preselected time.

4. The invention of claim 2 in which first said change effecting means comprises an oscillator, means for heterodyning the output of said oscillator with the output of said carrier generating means, and means for limiting the output of said heterodyning means to a frequency band different from the frequency band passed by said relatively large frequency band passing means, and in which said second change effecting means comprises means for restoring the picked up signal to a band of frequencies equal to that passed by said relatively large frequency band passing means and means for heterodyning the output of said restoring means with the output of said pickup means.

5. A detector for a signal having a carrier signal and an intelligence signal which is delayed from the carrier signal by a time duration proportional to the intelligence to be detected comprising means for differentiating the carrier signal, means for controllably delaying the differentiated signal, means for deriving the product of last said delaying means and the carrier signal, a low pass filter responsive to said product deriving means, and means for feeding back the output of said low pass filter to said controllable delaying means, said controllable delaying means being adapted to cause an increase in the maximum delay excursion as the output of said filter decreases.

6. The invention of claim 5 having means for effecting a fixed delay which is connected for additive cooperation with said controllable delaying means.

7. An intelligence communications system comprising a transmitter and a receiver;

said transmitter comprising means for generating a non-periodic energy signal, means for converting said non-periodic energy signal to an output signal having a time delayed reference carrier signal and a message signal which is delayed with respect to the reference carrier signal by a time duration proportional to an applied intelligence signal, and means for radiating the reference carrier signal and message signals from the same antenna;

said receiver comprising means for detecting said output signal radiated from said transmitter, means for differentiating the carrier signal of said output signal, means for controllably delaying the differentiated carrier signal, means for deriving a product of the output of said controllable delaying means and carrier signal, a low pass filter responsive to said product deriving means, and means for feeding back a portion of the output of said low pass filter to said controllable delaying means, said controllable delaying means being adapted to cause an increase in the maximum delayed excursion as the output of said filter decreases.

8. A delay modulated random energy intelligence communication system, including a transmitter comprising means for generating an output signal from a non-periodic energy signal, said output signal having a carrier signal and a message signal which has a time delay different from that of the carrier signal by a time duration proportional to the amplitude and frequency modulation of an applied intelligence signal, and means for radiating the carrier and message signals from an antenna simultaneously;

a receiver comprising means for picking up the carrier and message signals, means for differentiating the carrier signal, means for controllably delaying the differentiated signal, means for deriving the product of the output of said controllable delaying means and the carrier signal, a low pass filter responsive to said product deriving means, and means for feeding back a portion of the output of said low pass filter to said controllable delaying means, said controllable delaying means being adapted to cause an increase in the maximum delayed excursion as the output of said filter decreases, and means for effecting a fixed delay which is connected for additive cooperation with said controllable delaying means.