US5121208A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for reducing co-channel interference in an HDTV receiver
Assignee: Zenith Electronics LLC
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Filing: 1990-10-19
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Granted: 1992-06-09
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Expires: 2010-10-19
Abstract
Abstract NTSC co-channel interference is reduced in an HDTV receiver by developing an interference signal that is representative of the high energy components in the NTSC signal and subtracting the interference signal from the received HDTV signal to produce an enhanced HDTV signal for processing.
Inventors
- 👤 Richard W. Citta
- 👤 Gary J. Sgrignoli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:05
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/08; H04N7/0803; H04N11/00; H04N11/24; H04N11/28; H04N7/015; H04N9/00; H04N9/64; H04N9/646; H04N5/00; H04N5/44
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
60 words
A method of reducing NTSC co-channel interference in an HDTV receiver comprising: receiving both the NTSC and the HDTV signal; developing an interference signal representing substantially only high energy components of the NTSC signal; and combining said interference signal with the received signals to reduce the effects of the high energy components of said NTSC signal in said HDTV signal.
Claim 2
Independent Claim
60 words
A method of reducing NTSC co-channel interference in an HDTV receiver comprising: receiving both the NTSC and the HDTV signal; developing an interference signal representing substantially only high energy components of the NTSC signal; and combining said interference signal with the received signals to reduce the effects of the high energy components of said NTSC signal in said HDTV signal.
Claim 3
Dependent Claim
30 words
The method of claim 1 further including: developing a local signal corresponding to the carrier frequency of said NTSC signal; and using said local signal to develop said interference signal.
Claim 4
Dependent Claim
26 words
The method of claim 2 wherein said interference signal consists of low frequency, high energy components of said NTSC signal as determined by said local signal.
Claim 5
Independent Claim
80 words
A method of reducing NTSC co-channel interference in an HDTV receiver comprising: receiving both the NTSC and the HDTV signal; developing a local signal corresponding to the carrier frequency of said NTSC signal; developing an interference signal representing the low frequency, high energy components of said NTSC signal as determined by said local signal; and combining said interference signal with the received signals to reduce the effects of the high energy components of said NTSC signal in said HDTV signal.
Claim 6
Independent Claim
80 words
A method of reducing NTSC co-channel interference in an HDTV receiver comprising: receiving both the NTSC and the HDTV signal; developing a local signal corresponding to the carrier frequency of said NTSC signal; developing an interference signal representing the low frequency, high energy components of said NTSC signal as determined by said local signal; and combining said interference signal with the received signals to reduce the effects of the high energy components of said NTSC signal in said HDTV signal.
Claim 7
Dependent Claim
62 words
An HDTV receiver subject to simultaneous receipt of an HDTV signal and a co-channel NTSC signal comprising: means for developing a received signal including both said HDTV signal and said NTSC signal; means for developing an interference signal from said received signal representing the high energy components of said NTSC signal; and means for subtracting said interference signal from said received signal.
Claim 8
Dependent Claim
62 words
An HDTV receiver subject to simultaneous receipt of an HDTV signal and a co-channel NTSC signal comprising: means for developing a received signal including both said HDTV signal and said NTSC signal; means for developing an interference signal from said received signal representing the high energy components of said NTSC signal; and means for subtracting said interference signal from said received signal.
Claim 9
Dependent Claim
32 words
The receiver of claim 5 further including means for developing a local signal corresponding to the carrier of said NTSC signal and amplitude modulating said local signal to develop said interference signal.
Claim 10
Dependent Claim
18 words
The receiver of claim 6 wherein said interference signal comprises the low frequency components of said NTSC signal.
Claim 11
Dependent Claim
20 words
The receiver of claim 7 further including comb filter means for developing both HDTV sync information and said interference signal.
Claim 12
Dependent Claim
62 words
For use in a noncompatible HDTV/NTSC television system, an HDTV receiver subject to simultaneous receipt of an HDTV signal and an interfering co-channel NTSC signal comprising: means for developing a received signal including both said HDTV signal and said interfering co-channel NTSC signal; and means for reducing the magnitude of said interfering co-channel NTSC signal without significantly affecting said received HDTV signal.
Claim 13
Dependent Claim
62 words
For use in a noncompatible HDTV/NTSC television system, an HDTV receiver subject to simultaneous receipt of an HDTV signal and an interfering co-channel NTSC signal comprising: means for developing a received signal including both said HDTV signal and said interfering co-channel NTSC signal; and means for reducing the magnitude of said interfering co-channel NTSC signal without significantly affecting said received HDTV signal.
Claim 14
Dependent Claim
59 words
The receiver of claim 9 wherein said reducing means comprise: means for deriving a local signal responsive to the carrier of said received NTSC signal; means for developing an interference signal, comprising the low frequency components of said NTSC signal, responsive to the amplitude of said local signal; and means for subtracting said interference signal from said received signal.
Claim 15
Dependent Claim
82 words
An HDTV receiver subject to simultaneous receipt of an HDTV signal and a co-channel NTSC signal comprising: means for developing a received signal including both said HDTV signal and said NTSC signal; means for deriving a local signal corresponding to the carrier of said NTSC signal; means for developing an interference signal responsive to the amplitude of said local signal representing the low frequency, high energy components of said NTSC signal; and means for subtracting said interference signal from said received signal.
Claim 16
Dependent Claim
82 words
An HDTV receiver subject to simultaneous receipt of an HDTV signal and a co-channel NTSC signal comprising: means for developing a received signal including both said HDTV signal and said NTSC signal; means for deriving a local signal corresponding to the carrier of said NTSC signal; means for developing an interference signal responsive to the amplitude of said local signal representing the low frequency, high energy components of said NTSC signal; and means for subtracting said interference signal from said received signal.
Claim 17
Dependent Claim
28 words
The receiver of claim 11 wherein said received signal is at IF frequency and wherein said developing means includes bandpass means, synchronous detector means and line averaging means.
References Cited (Backward Citations)
US4794447A
Cited
US4870489A
Cited
US4837611A
Cited
US4888641A
Cited
US4907069A
Cited
US4918515A
Cited
US4916525A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-06-09 | 1995-12-09 | 1996-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-09 | 1999-12-09 | 2000-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-09 | 2003-12-09 | 2004-06-09 | $7700.00 | Window Closed / Lapsed |