Television – Image signal processing circuitry specific to television – Noise or undesired signal reduction
Patent
1993-08-06
1995-03-21
Groody, James J.
Television
Image signal processing circuitry specific to television
Noise or undesired signal reduction
348607, 348711, 455307, 375350, H04N 544, H04N 1100, H04N 521
Patent
active
054000840
ABSTRACT:
A complex NTSC interference canceler for eliminating NTSC signal interference from in-phase and quadrature phase received television signals including both a desired HDTV signal and NTSC interference signal. The complex NTSC interference canceler uses a bank of complex recursive notch filters with adjustable center frequencies to isolate the NTSC signal's major components, i.e. the picture carrier signal, the chrominance subcarrier signal and the audio carrier signal. A single complex 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, the interference signal components are subtracted from the in-phase and quadrature phase received television signals.
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Groody James J.
Hitachi America Ltd.
Metjahic Safet
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