| 摘要 |
PROBLEM TO BE SOLVED: To reduce a confluent noise at a low cost without deteriorating an incoming signal. SOLUTION: A transmission line 2 consisting of a trunk line 4, branch lines 8a-8d, distribution lines 14a-14d and a service wire 18 interconnects a head end and a plurality of terminals 20, the head end transmits an outgoing signal to each terminal via the transmission line 2 and each terminal transmits an incoming signal to the head end via the transmission line 2. Each terminal is provided with a high frequency amplifier 46 to amplify the incoming signal. An attenuation circuit 62 attenuating the incoming signal is provided in the branch line 8a through which the incoming signal is delivered via the service wire 18 and the branch line 14a connected to each terminal 20 in confluent through the other branch lines 8b-8d and before being confluent to the other branch liens 8b-8d. A gain of the high frequency amplifier 46 is decided such that the reduction in the level of the incoming signal when the attenuation circuit 62 attenuates a noise superimposed on the incoming signal delivered through the service wire 18 and the branch lines 14a connected to each terminal can be compensated.
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