The present invention at least one of which in a communication system using a relay scheme, the base station first exists in the base station its own zone of the first region and the area of the first region is the second region are overlapped third region of the relay station in the first time interval receiving a first signal from the mobile station is the first mobile station and the relay station is a second at least one mobile station is present in the second of the first region and does not overlap the area of the fourth region of the regions in the first time interval receiving a second signal from the mobile station, receiving the first signal from the first mobile station, and transmitting a third signal to said relay station comprises a first signal and a second signal at a second time interval to the base station and detects the second signal by removing the first signal receiving the third signal, and in the third signal from the base station, said second time interval. A relay, a relay station, the interference signal, the interference cancellation