Television – Image signal processing circuitry specific to television – Noise or undesired signal reduction
Patent
1993-01-13
1994-06-28
Groody, James J.
Television
Image signal processing circuitry specific to television
Noise or undesired signal reduction
375103, 455307, 348725, 348736, H04N 544, H04N 1100, H04N 700
Patent
active
053251881
ABSTRACT:
An NTSC interference canceler for eliminating NTSC signal interference from a HDTV signal uses recursive notch filters with adjustable center frequencies to isolate an NTSC signal's major components, i.e. the picture carrier signal, the chrominance subcarrier signal and the audio carrier signal. A single filter is used to isolate each NTSC interference signal component, with each particular filter's center frequency being adjusted to match the frequency of the particular NTSC interference signal component to be isolated by the filter. Each filter's gain may be either fixed or dynamically adjusted to match the amplitude of the NTSC interference signal component. Once isolated, these interference signal components are subtracted from the received television signal which includes both the NTSC interference signal and the HDTV signal. In this manner, the NTSC interference is removed from the HDTV signal.
REFERENCES:
patent: 3744015 (1973-07-01), Marimon et al.
patent: 3967102 (1976-06-01), McCown
patent: 4199660 (1980-04-01), Dill et al.
patent: 4480236 (1984-10-01), Harris
patent: 4549312 (1985-10-01), Michaels et al.
patent: 4589083 (1986-05-01), LeDinh et al.
patent: 4667225 (1987-05-01), Kanda
patent: 4673982 (1987-06-01), Tam et al.
patent: 4954785 (1990-09-01), Segaram
patent: 5031194 (1991-07-01), Crespo et al.
patent: 5051963 (1991-09-01), Linville, Jr. et al.
patent: 5086340 (1972-02-01), Citta et al.
patent: 5087975 (1992-02-01), Citta et al.
patent: 5121208 (1992-06-01), Citta et al.
patent: 5157697 (1992-10-01), Anauri et al.
patent: 5162900 (1992-11-01), Citta
patent: 5222106 (1993-06-01), Satoh et al.
patent: 5235612 (1993-08-01), Stilwell et al.
patent: 5263048 (1993-11-01), Wade
McMann, R. H., et al., "A Digital Noise Reducer for Eucoded NTSC Signals", SMPTE Journal, Mar. 1978, vol. 87, No. 3, pp. 129-133.
E. P. Darbyshire, "Narrowband Interference Identification and Rejection Applied to Baseband Radio Signals", IEE Conference Publication No. 325. Published by IEE, Michael Faraday House, Stevenage, Engl., 1990, pp. 217-221.
General Instrument Corporation Videocipher Division, "Digicipher HDTV System Description", Aug. 22, 1991, pp. 31-40, 49-60.
Zenith, AT&T, "Technical Details, Digital Spectrum Compatible", Sep. 23, 1991, pp. 3-4, 51-56, 67-110.
David Sarnoff Research Center, Philips Laboratories, "Advanced Digital Television, System Description", Jan. 20, 1992, pp. v-vii, 69-113.
Advanced Television Research Consortium, "Advanced Digital Television, Prototype Hardware Description", Feb. 12, 1992, pp. 8-10, 45-57.
Daltorro, Jon, "The Implementation of Recursive Digital Filters for High-Fidelity Audio", J. Audio Eng. Soc., vol. 36, No. 11, Nov. 1988, pp. 851-877.
Groody James J.
Hitachi America Ltd.
Metjahic Safet
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