Patent ID: 8855041

Claim:
A radio relay station configured to relay communications between a radio base station and a radio terminal, the radio relay station comprising: a first transceiver unit configured to transmit and receive a first signal for which a first frequency band is used, to and from the radio base station; a second transceiver unit configured to transmit and receive a second signal for which a second, frequency band is used, to and from the radio terminal; and a controller configured to control the first transceiver unit and the second transceiver unit, wherein the second transceiver unit includes a frequency shifter configured to shift the second frequency band, when receiving the second signal from the second transceiver unit, the first transceiver unit measures a signal level of the second signal in the first frequency band, and the controller adjusts a shifting amount of the second frequency band in the frequency shifter so that the signal level measured by the first transceiver unit is lowered, wherein the controller causes the first transceiver unit to make a plurality of measurements of the signal level while changing the shifting amount, and the controller determines the shifting amount set in a measurement in which the lowest signal level is measured among the plurality of measurements as the shifting amount to be set for the frequency shifter.