When a closed loop transmission diversity control is performed by controlling the phase of the transmission signals from the plurality of antennas according to feedback information noticed by the mobile station to transmit the signals, an antenna verification on-off control unit 370 controls the on-off of an antenna verification process of estimating the phase of the transmission signals from the plurality of antennas according to the information about the channel of the signals transmitted in the uplink from the mobile station to a radio base station. Thus, depending on the channel type (for example, a packet channel, a voice channel, etc.), the on-off control is performed on the antenna verification process, thereby performing easier and more appropriate control and improving the quality of a channel.