| 摘要 |
<P>PROBLEM TO BE SOLVED: To automatically adjust each upload and downroad signal level in a radio base station and a satellite station at specified levels by a simple constitution. <P>SOLUTION: In an interface 12, a pilot signal P at a specified level is generated by a pilot-signal generator 120, and a downroad transmitting signal 111 from the radio base station 11 is multiplied by a coupler 121. A multiple signal is amplified at a constant gain by a downroad-signal amplifier 122, converted into a downroad light signal by an electric/optical converter 123, wavelength-multiplexed by an optical multiplexing-branching filter 124 and sent out to an optical fiber 15 and transmitted to the satellite station 13. In the satellite station 13, the downroad light signal separated in wavelength by the optical multiplexing-branching filter 124 is converted into a downroad electric signal by an optical/electric converter 125, and the pilot signal P is separated by a branching filter 133. A gain controller 130 detects the absolute level of the pilot signal P, and outputs a gain control signal G1 bringing a level value at a predetermined normal value. In a downroad-signal gain variable amplifier 134 and an ascent-signal gain variable amplifier 136, a downroad transmitting signal and an ascent receiving signal are amplified by gains controlled by the gain control signal G1, respectively. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
