Patent US5452015A successfully refreshed from Google Patents.
US5452015A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for combating co-channel NTSC interference for digital TV transmission
Assignee: Funai Electric Co Ltd
•
Filing: 1994-02-10
•
Granted: 1995-09-19
•
Expires: 2014-02-10
Abstract
Abstract A rejection filter for use at an ATV receiver which is designed to process co-channel interference so as to produce at the filter output of the filter, a residual interference spectrum which is as flat as possible. The filter exploits the fact that only the picture and the sound carriers need to be sufficiently attenuated and cancels NTSC co-channel interference with only a small degradation in performance when AWGN is also present.
Inventors
- 👤 Samir N. Hulyalkar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 07:35
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H04N5/21; H04N5/211; H04L; H04L25/00; H04L25/02; H04L25/03; H04L25/03006; H04L25/03178; H04L25/03312; H04L25/03318; H04N21/00; H04N21/40; H04N21/41; H04N21/426; H04L2025/0335; H04L2025/03375; H04L2025/03382; H04L2025/03433; H04L2025/03439; H04L2025/03445; H04L2025/03471; H04L2025/03484; H04L2025/03496
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
67 words
A television receiver comprising: means for receiving a transmitted signal having an encoded digital television signal component and a co-channel interference component; means for flattening the frequency spectrum of the co-channel interference component to produce a filtered encoded digital television signal from the transmitted signal, said means for flattening including a prediction filter having fixed coefficients; and decoder means for decoding the filtered encoded digital television signal.
Claim 2
Dependent Claim
67 words
A television receiver comprising: means for receiving a transmitted signal having an encoded digital television signal component and a co-channel interference component; means for flattening the frequency spectrum of the co-channel interference component to produce a filtered encoded digital television signal from the transmitted signal, said means for flattening including a prediction filter having fixed coefficients; and decoder means for decoding the filtered encoded digital television signal.
Claim 3
Dependent Claim
30 words
A television receiver as claimed in claim 1, wherein the encoded digital television signal is a precoded encoded digital television signal, and said prediction filter operates on the transmitted signal.
Claim 4
Dependent Claim
28 words
A television receiver as claimed in claim 1, wherein said prediction filter further has a gain factor, and said coefficients are restricted to values in the set {-1,0,+1}.
Claim 5
Dependent Claim
31 words
A television receiver as claimed in claim 1, wherein said prediction filter operates on a difference signal, said difference signal being the difference between the transmitted signal and a past-decision signal.
Claim 6
Dependent Claim
41 words
A television receiver as claimed in claim 1, wherein said prediction filter operates on a difference signal, said difference signal being the difference between the transmitted signal delayed by a time interval and a past-decision signal delayed by said time interval.
Claim 7
Dependent Claim
21 words
A television receiver as claimed in claim 5, wherein the time interval is substantially equal to a NTSC line interval delay.
Claim 8
Dependent Claim
95 words
A television receiver comprising: means for receiving a transmitted signal having an encoded digital television signal component which has had its symbols interleaved at a transmitter and a co-channel interference component; means for flattening the frequency spectrum of the co-channel interference component to produce a filtered encoded digital television signal from the transmitted signal, said means for flattening including a prediction filter having fixed coefficients; symbol de-interleaving means for de-interleaving the symbols of the filtered encoded digital television signal to produce a de-interleaved digital television signal; decoder means for decoding the de-interleaved digital television signal.
Claim 9
Dependent Claim
95 words
A television receiver comprising: means for receiving a transmitted signal having an encoded digital television signal component which has had its symbols interleaved at a transmitter and a co-channel interference component; means for flattening the frequency spectrum of the co-channel interference component to produce a filtered encoded digital television signal from the transmitted signal, said means for flattening including a prediction filter having fixed coefficients; symbol de-interleaving means for de-interleaving the symbols of the filtered encoded digital television signal to produce a de-interleaved digital television signal; decoder means for decoding the de-interleaved digital television signal.
Claim 10
Dependent Claim
30 words
A television receiver as claimed in claim 7, wherein the encoded digital television signal is a precoded encoded digital television signal, and said prediction filter operates on the transmitted signal.
References Cited (Backward Citations)
US3652992A
Cited
US4833693A
Cited
US5086340A
Cited
US5121203A
Cited
US5087975A
Cited
US5181112A
Cited
US5325188A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-09-18 | 1999-03-20 | 1999-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-09-18 | 2003-03-20 | 2003-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-09-18 | 2007-03-20 | 2007-09-19 | $7700.00 | Window Closed / Lapsed |