| 摘要 |
A television signal transmission signal comprises a suppressed carrier, VSB signal having respective Nyquist slopes at the lower and upper edges of a 6MHz television channel, the center frequency of the Nyquist slope at the lower edge of the channel being substantially coincident with the frequency of the suppressed carrier, and the pilot signal in quadrature relation with the suppressed carrier. The suppressed carrier is modulated by an N-level digitally encoded signal having a sample rate fs substantially equal to three times the NTSC color subcarrier frequency, with the frequency of the color subcarrier being less than the co channel NTSC picture carrier by an amount equal to about fs/12. The received signal is demodulated by a synchronous detector in response to the received pilot signal and interfering NTSC beat components are attenuated by a linear filter having notches at fs/12, 5fs/12 and fs/2. The output of the filter comprises an M-level signal, where M = greater than N, which is converted to a N-level output signal representing the televised image.
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