| 摘要 |
PURPOSE:To easily take synchronization economically by using a ground system ISDN master clock especially so as to modulate and decode a video image or an audio signal in the satellite communication system in which digitized video image or audio signal is sent. CONSTITUTION:In the satellite communication system in which a transmission earth station 2 sending a digitized video image or a digitized audio signal via an artificial satellite 1 and a reception earth station 3 receiving the video image or the audio signal sent from the transmission earth station 2 make transmission reception of the video image or the audio signal synchronously with each other, the transmission earth station and the reception earth station extract synchronization clock from a ground system ISDN master clock respectively to keep the clock synchronization between the transmission earth station and the reception earth station thereby taking synchronization with each other. |
