Method for realizing automatic gain compensation of simulative optic-fiber repeater according to light detection

The invention discloses a method for realizing automatic gain compensation of a simulative optic-fiber repeater according to light detection. The method comprises the following steps: when a far-end machine starts up, attenuation values of an uplink radio frequency attenuator and a downlink radio frequency attenuator are set to maximum values; a PD (Potential Difference) detection voltage is sampled by a single-chip microcomputer; the current voltage value is stored, and the decrement can be obtained by searching a light receiving power and detection voltage corresponding table; the decrement of the radio frequency attenuator can be controlled by the decrement obtained by searching the table through the single-chip microcomputer; the PD detection voltage is sampled at a fixed time by the single-chip microcomputer; the PD detection voltage and the stored voltage are compared, when a difference of the sampled voltage value and the voltage value stored by a register is greater than 20 mV, the new data is stored