| 摘要 |
PURPOSE:To reduce the cost of a transmitter and receiver and obtain the flexibility of service, and utilize a transmission line with plural transmission forms by employing a packet signal form for the transmission line integrally and using the high frequency stage of the transmitter and receiver in common. CONSTITUTION:The signal form of a resource for a televison signal is converted by an encoder I 2, and the signal is modulated by an FM modulator 3 and sent to a changeover switch 7. Speech and other data are converted by an encoder II5 into a digital signal, which is modulated and then sent to a switch 7. The switch 7 switches a television packet signal and a speech/data packet signal on time-division basis to obtain a transmission line signal. The signal on the transmission line is separated by a switch 8 into the televison packet signal and speech/data packet signal on time-division basis. The television packet signal demodulated by a demodulator 9 is converted to the signal form of a transmission side resource by decoder I 10 and the speech/data packet signal, on the other hand, is also converted to the signal form of the transmission side resource by a decoder II12. |
