Patent US3558199A successfully refreshed from Google Patents.
US5111298A
Expired / Lapsed
US
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Method and apparatus for communication channel identification and signal restoration
Assignee: Philips North America LLC
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Filing: 1991-04-30
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Granted: 1992-05-05
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Expires: 2011-04-30
Abstract
Abstract A method and apparatus for improved ghost cancellation for use in particular in television receivers. The sequence of coefficients derived from a received GCR (Ghost Cancellation Reference) signal, is further processed to effect a transfer of energy from minor echo coefficients to major echo coefficients thereby improving the overall performance of the ghost cancellation device.
Inventors
- 👤 David Koo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:24
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H04N5/21; H04L; H04L1/00; H04L1/24; H04L1/242; H04L25/00; H04L25/02; H04L25/0202; H04L25/0212; H04L25/024; H04L25/0242; H04L25/0244; H04N5/211; H04N7/00; H04N7/08
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
113 words
A method for removing channel induced distortion from signals, comprising the steps of: a) receiving a test signal after it has passed through and been distorted by a communication channel; b) deriving from said received test signal a sequence of coefficients to be used with at least one filter; c) subjecting said sequence of coefficients to a transformation process so as to transform it from its time domain state to its frequency domain state; d) widening the bond width of said sequence of coefficients in said frequency domain state; and e) subjecting said widened bandwidth frequency domain state to an inverse transform process so as to transform it into its time domain state.
Claim 2
Independent Claim
113 words
A method for removing channel induced distortion from signals, comprising the steps of: a) receiving a test signal after it has passed through and been distorted by a communication channel; b) deriving from said received test signal a sequence of coefficients to be used with at least one filter; c) subjecting said sequence of coefficients to a transformation process so as to transform it from its time domain state to its frequency domain state; d) widening the bond width of said sequence of coefficients in said frequency domain state; and e) subjecting said widened bandwidth frequency domain state to an inverse transform process so as to transform it into its time domain state.
Claim 3
Dependent Claim
36 words
The method of claim 1 wherein said widening step comprises duplicating a plurality of non-zero values within said frequency domain state so as to replace values within said frequency domain state which are equal to zero.
Claim 4
Independent Claim
105 words
An apparatus for removing channel induced distortion from signals, comprising: a) means for receiving a test signal after it is passed through and been distorted by a communication channel; b) means for deriving from said received test signal a sequence of coefficients to be used with at least one filter; c) means for processing said sequence of coefficients so as to transform it from its time domain state to its frequency domain state; d) means for widening the bandwidth of said sequence of coefficients in said frequency domain state; and e) means for processing said widened bandwidth frequency domain state into its time domain state.
Claim 5
Independent Claim
105 words
An apparatus for removing channel induced distortion from signals, comprising: a) means for receiving a test signal after it is passed through and been distorted by a communication channel; b) means for deriving from said received test signal a sequence of coefficients to be used with at least one filter; c) means for processing said sequence of coefficients so as to transform it from its time domain state to its frequency domain state; d) means for widening the bandwidth of said sequence of coefficients in said frequency domain state; and e) means for processing said widened bandwidth frequency domain state into its time domain state.
Claim 6
Dependent Claim
11 words
A television receiver comprising the apparatus as claimed in claim 3.
Claim 7
Independent Claim
104 words
An apparatus for substantially eliminating ghosts occurring during the transmission of a television signal, wherein said television signal comprises a ghost cancellation reference signal, said apparatus comprising: a) means for receiving said television signal and for separating therefrom said ghost cancellation reference signal as distorted by said transmission; b) means for deriving from said received ghost cancellation reference signal a sequence of coefficients to be used with at least one filter, said sequence of coefficients having at least one first selected component and at least one second selected component; c) means for transferring energy from said second selected component to said first selected component.
Claim 8
Independent Claim
104 words
An apparatus for substantially eliminating ghosts occurring during the transmission of a television signal, wherein said television signal comprises a ghost cancellation reference signal, said apparatus comprising: a) means for receiving said television signal and for separating therefrom said ghost cancellation reference signal as distorted by said transmission; b) means for deriving from said received ghost cancellation reference signal a sequence of coefficients to be used with at least one filter, said sequence of coefficients having at least one first selected component and at least one second selected component; c) means for transferring energy from said second selected component to said first selected component.
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) | 1995-05-05 | 1995-11-04 | 1996-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-05-05 | 1999-11-04 | 2000-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-05-05 | 2003-11-04 | 2004-05-05 | $7700.00 | Window Closed / Lapsed |