US4458356A
Expired / Lapsed
US
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Carrier recovery circuit
Assignee: AT&T Inc
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Filing: 1982-07-02
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Granted: 1984-07-03
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Expires: 2002-07-02
Abstract
Abstract A carrier recovery circuit is disclosed for use in the receiver of a digital transmission wherein channels of data are formed by demodulating incoming quadrature-related carriers using receiver-generated, quadrature-related carriers. Phase alignment of the receiver-generated carriers to the incoming carriers is provided by integrated data from a preselected channel when the channels of data correspond to preselected regions in the signal space diagram.
Inventors
- 👤 William W. Toy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:26
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/18; H04L27/22; H04L27/227; H04L27/2271; H04L27/2273; H04L27/0014; H04L2027/0024; H04L2027/0026; H04L2027/0028; H04L2027/0044; H04L2027/0053; H04L2027/0057
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
110 words
A carrier recovery circuit for use in the receiver of a digital transmission system wherein channels of data are formed by demodulating quadrature-related carriers, said circuit comprising means for generating quadrature-related local carriers, first means for integrating the data in a selected channel only when the data in said channels falls within a first predetermined region in a signal space diagram; second means for integrating the data in said selected data channel only when the data in said channels falls within a second different predetermined region in said signal space diagram; and means responsive to said first and said second integrating means for phase-aligning said local carriers with said carriers.
Claim 2
Dependent Claim
110 words
A carrier recovery circuit for use in the receiver of a digital transmission system wherein channels of data are formed by demodulating quadrature-related carriers, said circuit comprising means for generating quadrature-related local carriers, first means for integrating the data in a selected channel only when the data in said channels falls within a first predetermined region in a signal space diagram; second means for integrating the data in said selected data channel only when the data in said channels falls within a second different predetermined region in said signal space diagram; and means responsive to said first and said second integrating means for phase-aligning said local carriers with said carriers.
Claim 3
Dependent Claim
37 words
The apparatus of claim 1 wherein said first and second integrating means integrate said selected channel data at a selected time when the data in said channels fall within said first and said second different predetermined regions.
Claim 4
Independent Claim
24 words
The apparatus of claims 1 or 2 wherein said first and said second different predetermined regions are adjacent quadrants in said signal space diagram.
Claim 5
Dependent Claim
24 words
The apparatus of claim 1 wherein said first and second different predetermined regions are predetermined portions of adjacent quadrants in said signal space diagram.
Claim 6
Independent Claim
28 words
The apparatus of claims 1 or 2 wherein said first and said second different predetermined regions are different pairs of diagonally opposing quadrants in said signal space diagram.
Claim 7
Dependent Claim
29 words
The apparatus of claim 1 wherein said first and said second different predetermined regions are predetermined portions of different pairs of diagonally opposing quadrants in said signal space diagram.
Claim 8
Independent Claim
21 words
The apparatus of claims 1 or 2 wherein said first and said second integrating means each provide a weighted data average.
Claim 9
Dependent Claim
24 words
The apparatus of claim 2 wherein said first and second different predetermined regions are predetermined portions of adjacent quadrants in said signal space diagram.
Claim 10
Dependent Claim
29 words
The apparatus of claim 2 wherein said first and said second different predetermined regions are predetermined portions of different pairs of diagonally opposing quadrants in said signal space diagram.
Claim 11
Dependent Claim
104 words
A carrier recovery circuit for use within the receiver of a digital transmission system wherein channels of data are formed by demodulating quadrature-related carriers using locally-generated quadrature-related carriers, said circuit comprising means for comparing the data in said channels to associated channel thresholds; first means responsive to a first result of said comparisons for integrating the data in a preselected channel; second means responsive to a different result of said comparisons for integrating the data in said preselected channel; and means responsive to the data integrated in response to said first and said second result for phase aligning said locally-generated carriers with said carriers.
Claim 12
Dependent Claim
104 words
A carrier recovery circuit for use within the receiver of a digital transmission system wherein channels of data are formed by demodulating quadrature-related carriers using locally-generated quadrature-related carriers, said circuit comprising means for comparing the data in said channels to associated channel thresholds; first means responsive to a first result of said comparisons for integrating the data in a preselected channel; second means responsive to a different result of said comparisons for integrating the data in said preselected channel; and means responsive to the data integrated in response to said first and said second result for phase aligning said locally-generated carriers with said carriers.
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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) | 1987-07-03 | 1988-01-02 | 1988-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-03 | 1992-01-02 | 1992-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-03 | 1996-01-02 | 1996-07-03 | $7700.00 | Window Closed / Lapsed |