The present invention aims to provide a radio base station that has equivalently high reception sensitivity without increasing the number of antenna elements while keeping the utilization efficiency of time slots high. The radio base station comprises a radio unit 101 and a radio unit 102. Two time slots, one at each radio unit, are allocated to a mobile station. After a signal transmitted from the mobile station is received and demodulated, a piece of data received by the radio unit 101 is compared with a piece of data received by the radio unit 102 so that one of the pieces of data that has fewer errors is selected.