Composite shift keying communication system
First Claim
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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Accused Products
Abstract
A Composite Shift Keying (CSK) modulation technique is described which provides enhanced error detection capability in a noisy transmission medium, such as an AC power line. A modulating binary signal causes the generation of two of three possible transmitted signals, and when the modulating binary signal is idle, no signal is transmitted. When the modulating signal is active, a single frequency qualifying signal (of radian frequency Wqt) is transmitted. If the active binary signal is a logical 0, an additional single frequency (of radian frequency W0) is transmitted along with Wqt. If the active binary signal is a logical 1, a different single frequency (of radian frequency W1) is transmitted with Wqt.
247 Citations
22 Claims
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1. A composite shift key method of communication for binary signals, comprising:
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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 at b. 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 at c. 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A composite shift key communication system for binary signals comprising
a transmitter which transmits 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, said transmitter transmitting a first summed signal of a first signal at a first frequency W1 with the qualifying signal at the qualifying signal frequency Wqt, 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 said transmitter transmitting a second summed signal of a second signal at a second frequency W0 with the qualifying signal at the qualifying signal frequency Wqt, 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 said transmitter 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.
- 13. A composite shift key method communication system for binary signals as claimed in claim l2, further comprising a receiver for receiving the transmitted signals, said receiver identifying a binary one signal only when the qualifying signal Wqt and the first frequency signal W1 are received simultaneously, and said receiver identifying a binary zero signal only when the qualifying signal Wqt and the second frequency signal W0 are received simultaneously.
Specification