| 摘要 |
PURPOSE:To send a video signal together with an audio PCM signal with high quality and a data signal through a transmission channel of 6MHz by transmitting a television signal formed resulting from the application of residual side band amplitude modulation of spectrum arrangement having a Nyquist slope to a 1st carrier and from the application of digital modulation to a 2nd carrier. CONSTITUTION:The spectrum arrangement is adopted, in which a video carrier fv is arranged to a frequency location by 4.5MHz from the upper end of a transmission channel 1 whose band width is 6MHz, a video transmission band 2 of the residual side band amplitude modulation system is provided and the Nyquist slope is provided to the frequency band around the carrier fv, and an audio carrier 1 fs having a frequency of fv-fs=(1/4)fsc (fsc is a frequency of a chrominance subcarrier subject to frequency insert and multiplex onto a video signal modulated by a chrominance signal) is allocated to an idle band in excess of 1MHz caused at the lower end of the transmission channel 1 and an audio transmission band 3 using the digital modulation system such as the 4-phase DPSK system and modulated by an audio signal is formed. Thus, the audio PCM transmission with high quality and data transmission are implemented. |
