The present invention provides a mobile station for communicating with a radio base station wherein a closed loop transmit diversity for transmission with use of a plurality of antennas is applied to the radio base station, comprising: a feedback information control unit controlling a feedback information control process based on the number of radio base stations simultaneously communicating with the mobile station. The mobile station can generate feedback information suitable for a shared physical channel in an intra-cell handover. On the other hand, the mobile station can generate feedback information suitable for a dedicated physical channel in an inter-cell handover.