| 摘要 |
PURPOSE:To change over and select a sound according to the desire of a present viewer by multiplexing data of an FM broadcasting channel corresponding to a sound area of a TV broadcasting channel in a center side, and tuning the FM broadcasting channel to the TV broadcasting channel selected in a receiver side by the use thereof. CONSTITUTION:In the center side, a data multiplexing encoder 18 is disposed, the data of a data signal generator 15 is inputted to an FM data modulator 16, added to the output of a video and first sound source 1 by an adder 17 after an FM modulation, and as a result, said data is multiplexed on the signal area of the TV broadcasting channel, In a terminal side, the signal from a trunk line is separated into a TV frequency band and an FM frequency band by a wave separator 46, a changeover switch 28 selects the first sound or the second sound by manual operation of the viewer and a PLL circuit feeds PLL data according to the selection. The tuned signal passes through an IF amplifier 31, and an FM detector 32, is stereo-demodulated in an MPX circuit 33 and a multiplex broadcasting service can be obtained. |
