| 摘要 |
PURPOSE:To send/receive a signal while keeping high line quality by detecting a least narrow band signal channel, informing the information of this channel to a reception station side and sending a narrow band signal through the noticed channel to a receiver side. CONSTITUTION:A high frequency section 313 receives a broad band signal from a satellite, converts the signal into an intermediate frequency signal, the signal is fed to a reception circuit 312, which converts the signal into a base band signal and the signal is fed to a reception level statistic processing section 311. The circuit 311 observes statistically the reception level to detect a channel whose signal level is lowest. The frequency information of the detected channel is informed to an earth station E1 via a transmission control circuit 310 and a contact line by using a transmission frequency information line 305. Upon the receipt of the frequency information of the lowest channel from the circuit 311, the circuit 310 converts the base band signal inputted from a terminal equipment into an intermediate frequency with a carrier of the frequency noticed and the high frequency section 313 converts the signal into a high frequency signal and it is sent to the satellite. |
