| 摘要 |
PURPOSE:To select a signal precisely by superposing a tone signal having the same level as that of other repeater stations on signals received and demodulated in respective repeater stations and controlling the gain of an AGC amplifier in a base station so that the tone signals in signals sent from respective repeater stations are uniformed at the same level in a mobile radio communication system. CONSTITUTION:A repeater station 8 receives and demodulates a radio wave sent from a mobile station by a receiving device 9, synthesizes a tone signal oscillated from an oscillator 11 so as to be made uniform at the same level in respective repeater stations by a synthesizer 10 and transmits the tone signal to the base station 7. A repeater station 8' also transmits its tone signal similarly to the base station 7. The base station 7 amplifies the signals transmitted from the repeater stations 8, 8' by AGC amplifiers 12, 12' respectively and detects the tone signals in their outputs by narrow band filters 13, 13' and detectors 14, 14' as the control voltages of the AGC amplifiers 12, 12' to fix the levels of the tone signals in the outputs of the AGC amplifiers 12, 12'. Consequently, the dispersion of the attenuation of the signals from the repeater stations 8, 8' to the base station 7 is compensated and respective signals are sent equivalently with equal attenuation, so that the receiving state can be correctly decided by a noise variable in the signal. |
