| 摘要 |
PROBLEM TO BE SOLVED: To eliminate deterioration in speech quality of all relay waves by separating received radio waves from a mobile station for each frequency channel, amplifying them and using an automatic gain control means so as to keep levels of the radio waves to be a prescribed level or below. SOLUTION: Received radio waves with channel frequencies f2 , f4 from a mobile station by an antenna 16 are given to a distributer 36, from which they are distributed to frequency mixers 372 , 374 . Intermediate frequency signals corresponding to the channel frequencies f2 , f4 are selected by filters 382 , 384 , amplified by intermediate frequency amplifiers 412 , 414 and fed to frequency mixers 422 , 424 . The signals with the channel frequencies f2 , f4 are selected by filters 432 , 434 and synthesized by a synthesizer 44, and the synthesized signal is emitted to a base station from an antenna 12. Outputs from the intermediate frequency amplifiers 412 , 414 are given to automatic gain controllers 462 , 464 and outputs of them control respectively the attenuation of variable attenuators 392 , 394 . |
