| 摘要 |
PURPOSE:To improve information transmission speed by measuring a bit error rate of a satellite line and controlling the transmitter-receiver depending on the result of measurement so that error correction coding is stopped to give information to an error correction code redundancy bit or error correction coding is applied if the line state is deteriorated. CONSTITUTION:A signal 28 is sent from an antenna through a transmission reception branching device 9 is sent to a low noise amplifier 10 and a bit error rate measuring circuit 16 measures the bit error rate. If the bit error rate is lower than the preset specified threshold level, a synthesis circuit 4 outputs a synthesized output signal 24 including transmission information and the measured result of the bit error rate. If the bit error rate of a reception signal at a station B403 is increased and exceeds the threshold level measured in advance, the deteriorated line state is informed to a station A402 from the station 403 through a satellite line 405. A coding/non-coding command detection circuit 17 detects from the reception signal and an error correction coding signal 22 from a coding circuit 2 is selected as an input signal of the synthesis circuit 4. |
