| 摘要 |
PURPOSE:To make synchronization with random number series of the transmitting side and receiving side by sending spectrum diffusion carriers from the center side through a CATV circuit and making the orginating source of random number series to the center side by performing data communication through a lighting circuit by using this carrier. CONSTITUTION:A random number series generated in a random number generating device 11 is D/A-converted 12 and spectrum diffusion carriers are generated by a voltage control oscillator 13 based on the signal. The signal is converted to a specified high frequency by a converter 14 and given to a network 16, and composed with signals from a video source 15 and supplied to the terminal side. The terminal side receives this signal by a network 20, and controls by a digital controlling section 25 in a video signal processing secting 21, and outputs to a TV receiving set. On the other hand, diffusion carries separated in the network 20 are demodulated in a demodulator 22 and balance-modulated through a balanced modulator 23, and sent out to a lighting circuit through a lighting circuit interface 24. The center side adds diffusion carriers by a balanced detector 18 and performs balanced detection. |
