Receiver for a distribution network power line carrier communication system
First Claim
1. A receiver for receiving a carrier signal modulated by an information signal which is transmitted over a distribution network power line carrier communication system comprising:
- coupling means for providing a first signal in response to the carrier signal;
first amplifier means responsive to said coupling means for providing a second signal in response to said first signal, said first amplifier means including first feedback means for determining a gain of said first amplifier means;
means for producing a first and a second reference DC voltages;
first comparator means responsive to said first reference DC voltage and to said second signal;
second comparator means responsive to both said second reference DC voltage and to said second signal;
variable control means responsive to said first and said second comparator means, said variable control means cooperating with said first feedback means such that said gain of said first amplifier means is varied in response to the magnitude of said second signal;
high amplitude clipper means responsive to said second signal for providing a third signal;
second amplifier means responsive to said third signal for providing a fourth signal;
low amplitude clipper means responsive to said fourth signal for providing a sinusoidal clipped signal;
hard limiter means responsive to said sinusoidal clipped signal for providing a square wave signal; and
demodulator means responsive to said square wave signal for separating the information signal from the carrier signal.
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Accused Products
Abstract
A receiver for a distribution network power line carrier communication system is magnetically coupled to a distribution power line. A carrier signal, phase-shift keyed modulated by an information signal and carried by the distribution power line, is thereby coupled to the receiver circuitry. A first receiver amplification circuit includes an automatic gain control circuit, to prevent saturation of the receiver electronics, and a feedback circuit to determine the gain. The automatic gain control circuit utilizes a field effect transistor which cooperates with the amplifier'"'"'s feedback circuit to modify the gain. The drain source resistance of the field effect transistor is varied in accord with the magnitude of the received noise or modulated carrier signal to lower the amplifier'"'"'s gain when excessive positive or negative noise or modulated carrier signal peaks are encountered. The modulated carrier signal is then processed through several filter stages and further amplified. Finally, the information signal is removed from the modulated carrier by a phase shift keyed demodulator. The information is available for input to a remote device which is responsive thereto for performing any of a variety of automated functions.
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Citations
20 Claims
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1. A receiver for receiving a carrier signal modulated by an information signal which is transmitted over a distribution network power line carrier communication system comprising:
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coupling means for providing a first signal in response to the carrier signal; first amplifier means responsive to said coupling means for providing a second signal in response to said first signal, said first amplifier means including first feedback means for determining a gain of said first amplifier means; means for producing a first and a second reference DC voltages; first comparator means responsive to said first reference DC voltage and to said second signal; second comparator means responsive to both said second reference DC voltage and to said second signal; variable control means responsive to said first and said second comparator means, said variable control means cooperating with said first feedback means such that said gain of said first amplifier means is varied in response to the magnitude of said second signal; high amplitude clipper means responsive to said second signal for providing a third signal; second amplifier means responsive to said third signal for providing a fourth signal; low amplitude clipper means responsive to said fourth signal for providing a sinusoidal clipped signal; hard limiter means responsive to said sinusoidal clipped signal for providing a square wave signal; and demodulator means responsive to said square wave signal for separating the information signal from the carrier signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification