US5844949A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power line communication system
Assignee: General Electric Co
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Filing: 1996-10-09
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Granted: 1998-12-01
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Expires: 2016-10-09
Abstract
Abstract A system for communicating digital information over wires having a great deal of harmonic distortion, such as a power line, employs a transmitter which transmitter which creates a carrier wave for each of a plurality of signals to be sent. This carrier wave has frequency lobes positioned between the frequency lobes of the harmonic distortion. Each of the lobes of a single carrier signal is encoded with the same bit value during a given bit period. This signal is then mixed with any existing signal on the wire. At a remote receiver coupled to the wires, the signal is sensed, filtered, and Fourier transformed into coefficients. The signal-to-noise (S/N) ratio of each Fourier coefficient is determined by a novel S/N estimation technique. The coefficients are weighted based upon the S/N ratio estimation, and decoded, preferably by an inner product of the weighted Fourier coefficients. Additionally, the S/N ratio estimates could be time averaged before being used in the weighting and bit decoding.
Inventors
- 👤 John Erik Hershey
- 👤 Richard August Korkosz
- 👤 Gary Jude Saulnier
- 👤 Richard Charles Gaus, Jr.
- 👤 II Kenneth Brakeley Welles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:47
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/02; H04L1/04; H04B; H04B3/00; H04B3/54; H04L5/00; H04L5/02; H04L5/06; H04B2203/00; H04B2203/54; H04B2203/5404; H04B2203/5416; H04B2203/5462; H04B2203/5495
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
178 words
A system for communicating digital information over a wire having a harmonic interference frequency lobes comprising: a) a transmitter for transmitting message bits of a signal s 1 having: i. a carrier wave synthesis device for creating a carrier wave having a plurality of frequency lobes between interference lobes described by: ##EQU4## where t is time, f ik are frequencies between said harmonic interference lobes, M is the number of signal frequency lobes desired, α k , β k , are predetermined signal amplitudes, and φk,θk are predetermined phase offsets; ii. a bit encoder coupled to a timing device, the synthesis device, and said wire, which inverts a carrier waveform for a single bit period for one bit value of said message bit, and leaves the carrier wave unchanged for a second message bit value to create an encoded message; iii. a summation device coupled to the bit encoder and said wire, for summing the encoded message with existing signals on said wire; b) a receiver coupled to said wire which decodes the encoded message into message bits.
Claim 2
Independent Claim
178 words
A system for communicating digital information over a wire having a harmonic interference frequency lobes comprising: a) a transmitter for transmitting message bits of a signal s 1 having: i. a carrier wave synthesis device for creating a carrier wave having a plurality of frequency lobes between interference lobes described by: ##EQU4## where t is time, f ik are frequencies between said harmonic interference lobes, M is the number of signal frequency lobes desired, α k , β k , are predetermined signal amplitudes, and φk,θk are predetermined phase offsets; ii. a bit encoder coupled to a timing device, the synthesis device, and said wire, which inverts a carrier waveform for a single bit period for one bit value of said message bit, and leaves the carrier wave unchanged for a second message bit value to create an encoded message; iii. a summation device coupled to the bit encoder and said wire, for summing the encoded message with existing signals on said wire; b) a receiver coupled to said wire which decodes the encoded message into message bits.
Claim 3
Dependent Claim
64 words
The system for communicating digital information over a wire of claim 1 wherein the carrier wave synthesis device comprises: a) a timing device to determine bit periods, and bit rate timing; b) a storage device having a prestored carrier waveform; c) a playback device coupled to the timing device and the storage device for playing back the prestored waveform according to bit rate timing.
Claim 4
Dependent Claim
105 words
The system for communicating digital information over a wire of claim 1 wherein the receiver comprises: a) a sampler which converts a continuous signal into a series of discrete time samples; b) a quantizer coupled to the sampler which reduces the precision of the discrete time samples; c) a Fourier Transform device which performs a Fourier transform on the samples obtained at time t to result in Fourier coefficients X k (t); d) a decoder which performs an inner product of the Fourier coefficients X k (t), and determine if the inner product is above or below a predetermined threshold to produce decoded message bits.
Claim 5
Dependent Claim
80 words
The system for communicating digital information over a wire of claim 3 further comprising: a) a signal-to-noise (S/N) estimation device which estimates S/N based upon a reliability indication estimate |δ k | for each of the Fourier coefficients; b) a combiner which weights each of the Fourier coefficients X k (t) according to |δ k | to result in weighted Fourier coefficients X k (t) passed to the decoder used in place of X k (t) in determining bit decisions.
Claim 6
Dependent Claim
108 words
The system for communicating digital information over a wire of claim 3, further comprising: a) a signal-to-noise (S/N) estimation device which estimates |δ k | from Fourier coefficients acquired at times t and t-1, X k (t), X k (t-1), respectively according to the equation: ##EQU5## where X k (t-1)=x 1 +jy 1 and X k (t)=X 2 +jy 2 for each of the Fourier coefficients; b) a combiner which weights each of the Fourier coefficients X k (t) according to |δ k | to result in weighted Fourier coefficients X k (t) passed to the decoder used in place of X k (t) in determining bit decisions.
Claim 7
Dependent Claim
81 words
The system for communicating digital information over a wire of claim 4 further comprising: an averager coupled between S/N estimation device and the combiner for receiving a plurality of |δ k | estimates for Fourier coefficients X k (t) over time, and performing an average of |δ k | to result in an |δ k | for each lobe, provided to the combiner, and used in place of |δ k | to result in the modified Fourier coefficients X k (t).
Claim 8
Dependent Claim
46 words
The system for communicating digital information over a wire of claim 1 further comprising a plurality of transmitters each transmitting digital signals s i , where i ≠1 at frequencies between harmonic interference lobes, but at frequencies different than those of other transmitters of the system.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-11-30 | 2002-06-01 | 2002-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-30 | 2006-06-01 | 2006-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-30 | 2010-06-01 | 2010-12-01 | $7700.00 | Window Closed / Lapsed |