| 摘要 |
PURPOSE:To prevent erroneous carrier pull-in caused by the AFC operation of a reception demodulation part in a satellite communication system in which narrow band signals are adjacently arranged. CONSTITUTION:In the case of data transmission provided with a frame format equipped with a synchronous word for frame synchronization, on the transmission side, a pattern 4 peculiar for a transmitting channel is synchronized with data 1 by a multiplexing part 5 and transmitted as the synchronous word. On the reception side, the synchronous word of a desired receiving channel is compared with the synchronous word in the frame by a frame synchronization establishing part 15 and until they are coincident, a frequency sweeping control part 10 performs the local frequency sweeping control of a demodulator 9. |
