Patent US5720039A successfully refreshed from Google Patents.
US5720039A
Expired / Lapsed
US
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Satellite multiple access system with distortion cancellation and compression compensation
Assignee: Sirius XM Radio Inc
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Filing: 1996-11-01
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Granted: 1998-02-17
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Expires: 2016-11-01
Abstract
Abstract A multicarrier satellite communications system includes one or more satellites and one or more transmitters at generally terrestrial locations that transmit a plurality of signal carriers to the satellites which contain non-linear signal repeaters that produce inter-modulation noise or signal compression in the signal carriers. The noise is minimized/cancelled by adding to the signal carriers, at the generally terrestrial locations where the transmitters are located, noise-cancelling or signal compression-correcting signals.
Inventors
- 👤 Daniel Lieberman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:44
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/62; H04B7/00; H04B7/14; H04B7/15; H04B7/185; H04B7/1851; H04B7/18513; H04L; H04L5/00; H04L5/02; H04L5/06
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
135 words
A multicarrier, closed loop, satellite communications system comprises at least one satellite, and, at an at least one generally terrestrial location, at least one transmitter and a signal receiver for receiving signals from said at least one satellite said transmitter transmitting a plurality of harmonically-related signal carriers to said at least one satellite, said signal carriers generating inter-modulation noise in at least one non-linear signal repeater located in said at least one satellite, said system also including at said terrestrial location, means for analyzing and for identifying, in signal carriers received from said at least one satellite, a composite noise signal including said inter-modulation noise and a cancellation signal, and means for generating and adding to said transmitted signal carriers, said cancellation signal optimized to minimize said inter-modulation noise when added to said signal carriers.
Claim 2
Dependent Claim
135 words
A multicarrier, closed loop, satellite communications system comprises at least one satellite, and, at an at least one generally terrestrial location, at least one transmitter and a signal receiver for receiving signals from said at least one satellite said transmitter transmitting a plurality of harmonically-related signal carriers to said at least one satellite, said signal carriers generating inter-modulation noise in at least one non-linear signal repeater located in said at least one satellite, said system also including at said terrestrial location, means for analyzing and for identifying, in signal carriers received from said at least one satellite, a composite noise signal including said inter-modulation noise and a cancellation signal, and means for generating and adding to said transmitted signal carriers, said cancellation signal optimized to minimize said inter-modulation noise when added to said signal carriers.
Claim 3
Dependent Claim
32 words
The system of claim 1 further comprising, a signal generator that generates signals that are opposite in phase to, but are in all other respects substantially the same as, said inter-modulation noise.
Claim 4
Dependent Claim
68 words
The system of claim 2 further comprising, on each of said at least one satellite, a transmitter for transmitting said plurality of harmonically-related signal carriers to said transmitter at said at least one generally terrestrial location, said transmitter at said generally terrestrial location further comprising means for adjusting the phase and amplitude of said cancellation signal to approximately the same amplitude and opposite phase of said inter-modulation noise.
Claim 5
Dependent Claim
146 words
In a closed loop, multicarrier satellite communications system that includes at least one satellite with at least one non-linear signal repeater, and, located at least one terrestrial location, a signal receiver for receiving signals from said at least one satellite, and at least one transmitter that transmits a plurality of harmonically-related signal carriers to said at least one satellite, said signal carriers generating inter-modulation noise in said at least one non-linear signal repeater; a method comprising receiving said plurality of harmonically-related signal carriers at said at least one terrestrial location, analyzing said plurality of harmonically-related signal carriers to identify a composite noise signal including said inter-modulation noise and a cancellation signal, and adding to said plurality of harmonically-related signal carriers, at said terrestrial location, a cancellation signal, derived from said analyzing, that minimizes the identified inter-modulation noise when added to said plurality of harmonically-related signal carriers.
Claim 6
Dependent Claim
146 words
In a closed loop, multicarrier satellite communications system that includes at least one satellite with at least one non-linear signal repeater, and, located at least one terrestrial location, a signal receiver for receiving signals from said at least one satellite, and at least one transmitter that transmits a plurality of harmonically-related signal carriers to said at least one satellite, said signal carriers generating inter-modulation noise in said at least one non-linear signal repeater; a method comprising receiving said plurality of harmonically-related signal carriers at said at least one terrestrial location, analyzing said plurality of harmonically-related signal carriers to identify a composite noise signal including said inter-modulation noise and a cancellation signal, and adding to said plurality of harmonically-related signal carriers, at said terrestrial location, a cancellation signal, derived from said analyzing, that minimizes the identified inter-modulation noise when added to said plurality of harmonically-related signal carriers.
Claim 7
Dependent Claim
27 words
The method of claim 4 further comprising generating said cancellation signal opposite in phase to, but in all other respects substantially the same as, said inter-modulation noise.
Claim 8
Dependent Claim
34 words
The method of claim 5 further comprising adjusting as necessary, based on said analyzing, the phase and amplitude of said cancellation signal to approximately the same amplitude and opposite phase of said inter-modulation noise.
References Cited (Backward Citations)
US4038600A
Cited
US5015965A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-02-16 | 2001-08-18 | 2002-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-02-16 | 2005-08-18 | 2006-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-02-16 | 2009-08-18 | 2010-02-17 | $7700.00 | Window Closed / Lapsed |