摘要 |
An NTSC interference canceler for eliminating NTSC signal interference from a HDTV signal uses recursive notch filters with independently adjustable gains and 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 gain and center frequency being independently adjusted to match the amplitude and frequency of the particular NTSC interference signal component to be isolated by the filter. Once isolated, these interference signal components are substracted 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.
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