A multicarrier radio communication system includes a first mobile station located at a position where it is possible to directly communicate with the base station and to communicate with a radio relay station, and a second mobile station located at a position where it is impossible to directly communicate with the base station and it is possible to communicate with the radio relay station. For allocating subcarriers to signals, the base station determines an order of priority for signals destined for mobile stations on the basis of whether each mobile station is the first mobile station or not. The radio relay station allocates subcarriers to the signals, independently of subcarrier allocation made at the base station. For allocating subcarriers, the radio relay station determines an order of priority for signals on the basis of whether each mobile station is the first mobile station or not.