US4247944A
Expired / Lapsed
US
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V.29 Constellation detection method and apparatus
Assignee: Ricoh Co Ltd
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Filing: 1978-11-15
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Granted: 1981-01-27
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Expires: 1998-11-15
Abstract
Abstract V.29 constellation detection method and apparatus including a quadrant transformer for Processing the quantized real and imaginary component signals corresponding to a particular transmitted signal from a known set of transmitted signals by effectively rotating such components into first quadrant position while at the same time developing a quadrant designating signal or tag; a real part quantizer for determining within which of several real part regions the rotated real part component resides; a boundary line intersect selector for dynamically determining the imaginary part limits correspondence to the real part region selected; an imaginary part quantizer for determining within which of several imaginary part regions the rotated imaginary part component resides; and a constellation point selector which in response to the quantized real part, imaginary part information and quadrant information selects one of 16 constellation points as being the signal most likely received.
Inventors
- 👤 Bruce M. Sifford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:22
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/32; H04L27/34; H04L27/38; H04L27/02; H04L27/06
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
268 words
Detector apparatus for selecting from a plurality of constellation signal points arrayed in predetermined domains of a complex plane that signal point which lies closest to the complex plane location of a signal point corresponding to a received signal which has been equalized and converted to complex input signal form, comprising: quadrant transformation means for rotating the real and imaginary signal point identifying components of the complex input signal from a non-first quadrant location in the complex plane to a corresponding first quadrant location and for generating a rotated real part component signal, a rotated imaginary part component signal, and a quadrant signal indicating the original complex plane quadrant of the input signal; real part quantizing means responsive to said rotated real part component signal and operative to determine within which of a plurality of predetermined real part regions the rotated real part component signal is located and to develop a real part region signal commensurate therewith; boundary line intersect selection means responsive to said real part region signal and said rotated real part component signal and operative to generate a plurality of imaginary part boundary solution signals corresponding to points lying along predetermined boundary lines of domains crossed by a real part boundary region; imaginary part quantizing means responsive to said rotated imaginary part component signal and said imaginary part boundary solution signals and operative to develop an imaginary part region signal; and constellation point selection means responsive to said real part region signal, said imaginary part region signal and said quadrant signal, and operative to develop an output signal corresponding to one of the constellation points.
Claim 2
Dependent Claim
268 words
Detector apparatus for selecting from a plurality of constellation signal points arrayed in predetermined domains of a complex plane that signal point which lies closest to the complex plane location of a signal point corresponding to a received signal which has been equalized and converted to complex input signal form, comprising: quadrant transformation means for rotating the real and imaginary signal point identifying components of the complex input signal from a non-first quadrant location in the complex plane to a corresponding first quadrant location and for generating a rotated real part component signal, a rotated imaginary part component signal, and a quadrant signal indicating the original complex plane quadrant of the input signal; real part quantizing means responsive to said rotated real part component signal and operative to determine within which of a plurality of predetermined real part regions the rotated real part component signal is located and to develop a real part region signal commensurate therewith; boundary line intersect selection means responsive to said real part region signal and said rotated real part component signal and operative to generate a plurality of imaginary part boundary solution signals corresponding to points lying along predetermined boundary lines of domains crossed by a real part boundary region; imaginary part quantizing means responsive to said rotated imaginary part component signal and said imaginary part boundary solution signals and operative to develop an imaginary part region signal; and constellation point selection means responsive to said real part region signal, said imaginary part region signal and said quadrant signal, and operative to develop an output signal corresponding to one of the constellation points.
Claim 3
Dependent Claim
64 words
Detector apparatus as recited in claim 1 wherein said real part component signal and said imaginary part component signal each include a magnitude indicating portion and a quadrant indicating portion, and wherein said quadrant transformation means includes logic means responsive to said quadrant indicating portions and operative to convert said component signals into said rotated real part signal and said rotated imaginary part signal.
Claim 4
Dependent Claim
28 words
Detector apparatus as recited in claim 2 wherein said quadrant transformation means further includes counter means driven by said logic means and operative to develop said quadrant signal.
Claim 5
Dependent Claim
68 words
Detector apparatus as recited in claims 1, 2 or 3 wherein said real part quantizing means includes a comparator for comparing said rotated real part signal to each of a plurality of threshold level signals corresponding to the boundaries of real part regions and for developing said real part region signal as an indicator of within which of said real part regions said rotated real part signal falls.
Claim 6
Dependent Claim
47 words
Detector apparatus as recited in claims 1, 2 or 3 wherein said boundary line intersect selection means includes computation logic for determining the imaginary part intersection solutions to the boundary line equations defining the lines dividing said regions and for developing said boundary solution signals commensurate therewith.
Claim 7
Dependent Claim
66 words
Detector apparatus as recited in claim 5 wherein said real part quantizing means includes a comparator for comparing said rotated real part signal to each of a plurality of threshold level signals corresponding to the limits of said real part regions and for developing said real part region signal as an indicator of between which of the real part limits said rotated real part signal falls.
Claim 8
Dependent Claim
40 words
Detector apparatus as recited in claims 1, 2, 3 or 6 wherein said imaginary part quantizing means includes a comparator for comparing said rotated imaginary part signal to said boundary solution signals and for developing said imaginary part region signal.
Claim 9
Dependent Claim
44 words
Detector apparatus as recited in claim 7 wherein said boundary line intersect selection means includes computation logic for determining the imaginary part intersection solutions to the boundary line equations defining the lines separating said domains and for developing said boundary solution signals commensurate therewith.
Claim 10
Independent Claim
164 words
A method for selecting from a plurality of constellation signal points arrayed in predetermined domains of a complex plane that signal point which lies closest to the complex plane location of a point corresponding to a received signal, comprising the steps of: rotating the received point in the complex plane in 90° steps until the point lies in the first quadrant; determining within which of a plurality of predetermined real part regions intersecting various ones of said domains, the rotated point resides; determining within which of a plurality of imaginary part regions intersecting the selected real part region, the rotated point lies; selecting the first quadrant constellation point lying within the domain in which the intersection of the real part region and the imaginary part region resides; rotating the selected first quadrant constellation point back into the quadrant from which the rotated received point was originally located; and assigning the rotated constellation point the designation of the point into whose position it was rotated.
Claim 11
Independent Claim
164 words
A method for selecting from a plurality of constellation signal points arrayed in predetermined domains of a complex plane that signal point which lies closest to the complex plane location of a point corresponding to a received signal, comprising the steps of: rotating the received point in the complex plane in 90° steps until the point lies in the first quadrant; determining within which of a plurality of predetermined real part regions intersecting various ones of said domains, the rotated point resides; determining within which of a plurality of imaginary part regions intersecting the selected real part region, the rotated point lies; selecting the first quadrant constellation point lying within the domain in which the intersection of the real part region and the imaginary part region resides; rotating the selected first quadrant constellation point back into the quadrant from which the rotated received point was originally located; and assigning the rotated constellation point the designation of the point into whose position it was rotated.
Claim 12
Dependent Claim
44 words
A method as recited in claim 9 wherein the determination of within which of said real part regions said rotated point lies is made by comparing the real part component of said rotated point to limits associated with each of said real part regions.
Claim 13
Independent Claim
56 words
A method as recited in claims 9 or 10 wherein the determination of within which of said imaginary part regions said rotated point lies is made by solving certain region boundary line equations using the real part component of the rotated point and by comparing the imaginary part component of said rotated point to the solutions.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-27 | 1984-07-28 | 1985-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-27 | 1988-07-28 | 1989-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-27 | 1992-07-28 | 1993-01-27 | $7700.00 | Window Closed / Lapsed |