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Composite shift keying communication system

  • US 4,577,333 A
  • Filed: 09/13/1984
  • Issued: 03/18/1986
  • Est. Priority Date: 09/13/1984
  • Status: Expired due to Fees
First Claim
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1. A composite shift key method of communication for binary signals, comprising:

  • a. transmitting a summed signal having a qualifying signal at a qualifying signal frequency Wqt as one of the summed signal components only when binary data, either a binary zero or a binary one, is desired to be transmitted, by algebraically summing a first signal atb. a first frequency W1 with the qualifying signal at the qualifying signal frequency Wqt, to produce a first summed signal which is transmitted when a binary one is desired to be transmitted, such that a binary one transmitted signal is a composite summed signal of Wqt and W1, and by algebraically summing a second signal atc. a second frequency W0 with the qualifying signal at the qualifying signal frequency Wqt, to produce a second summed signal which is transmitted when a binary zero is desired to be transmitted, such that a binary zero transmitted signal is a composite summed signal of Wqt and W0; and

    d. ceasing transmission of the qualifying signal at the qualifying signal frequency Wqt as a transmitted signal or as a component of a composite summed signal when neither a binary zero nor a binary one is desired to be transmitted.

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