Patent US4627077A successfully refreshed from Google Patents.
US4627077A
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Modified QAM data point constellation for secondary channel signalling
Assignee: Paradyne Corp
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Filing: 1984-12-03
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Granted: 1986-12-02
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Expires: 2004-12-03
Abstract
Abstract A method of adding a secondary channel to a QAM signal mapped in the complex plane is provided. A pair of positions in the mapped complex plane is determined such that the positions are equi-distant from the origin and no greater from the origin than the distance from the origin to the position of the furthest mapped data point. For secondary channel communication, a data point is shifted from a normal mapped position to one or the other of the new positions with one of said positions assuming a binary "1" for the secondary channel and the other of said positions assuming a binary "0".
Inventors
- 👤 Thomas R. Armstrong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:43
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/32; H04L27/34; H04L27/345; H04L27/3461; H04L27/3472; H04B; H04B17/00; H04B17/0082; H04B17/0087
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
130 words
A method of adding a secondary channel to a QAM signal mapped in the complex plane with data points assuming normal positions on concentric rings comprising the steps of: (a) locating a pair of positions in the mapped complex plane (A and B) which are equi-distant from the origin and no farther from the origin than the distance from the origin to a selected data point; (b) assigning a binary "1" to the existence of a data point at one of said pair of positions and a binary "0" to the existence of a data point at the other of said pair of positions; (c) shifting said selected data point from a mapped normal positions to define said secondary channel, the other data points being kept at their normal positions.
Claim 2
Independent Claim
130 words
A method of adding a secondary channel to a QAM signal mapped in the complex plane with data points assuming normal positions on concentric rings comprising the steps of: (a) locating a pair of positions in the mapped complex plane (A and B) which are equi-distant from the origin and no farther from the origin than the distance from the origin to a selected data point; (b) assigning a binary "1" to the existence of a data point at one of said pair of positions and a binary "0" to the existence of a data point at the other of said pair of positions; (c) shifting said selected data point from a mapped normal positions to define said secondary channel, the other data points being kept at their normal positions.
Claim 3
Dependent Claim
29 words
The method in accordance with claim 1 wherein said selected data point normal position comprises a position no closer to the origin than any other normal data point position.
Claim 4
Dependent Claim
24 words
The method in accordance with claim 1 wherein said selected data point positions are on opposite sides of an axis of the complex plane.
Claim 5
Dependent Claim
18 words
The method in accordance with claim 1 wherein said selected data point positions are in the same quadrant.
Claim 6
Dependent Claim
21 words
The method of claim 1 wherein said selected data point is one of the points which are farthest from the origin.
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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) | 1989-12-01 | 1990-06-02 | 1990-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-01 | 1994-06-02 | 1994-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-01 | 1998-06-02 | 1998-12-02 | $7700.00 | Window Closed / Lapsed |