Patent ID: 8867124

Claim:
A relay station, comprising: a detection control unit, configured to continuously output an Alternating Current (AC) signal on which a replay signal is modulated; an output light stabilization unit, configured to extract a Direct Current (DC) signal from a current signal, wherein the current signal is obtained from partial output optical signals received by the relay station through photoelectric conversion; compare a current value of the DC signal with a first preset value, when the current value of the DC signal is greater than the first preset value, decrease a current value of a drive current, and when the current value of the DC signal is smaller than the first preset value, increase the current value of the drive current, wherein the drive current is used to drive generation of pump light; a reply stabilization unit, configured to extract a first AC signal from the current signal, wherein the first AC signal is a signal output after the AC signal on which the replay signal is modulated is adjusted once; obtain the DC signal from the output light stabilization unit, and subtract a valley value from a peak value of the first AC signal to obtain a difference value, divide the difference value by the current value of the DC signal to obtain a first ratio, compare the first ratio with a second preset value, when the first ratio is greater than the second preset value, decrease a gain value, and when the first ratio is smaller than the second preset value, increase the gain value, wherein the gain value is used to adjust an amplitude value of the AC signal on which the reply signal is modulated; an adjustable gain amplification unit, configured to adjust the amplitude value of the received AC signal on which the reply signal is modulated according to the gain value, and output an adjusted second AC signal on which the reply signal is modulated; and a pump light output unit, configured to drive the generation of the pump light after coupling the second AC signal and the adjusted drive current, and carry the reply signal on the output optical signal through the pump light and adjust a strength of the output optical signal.