A base station that communicates with a user equipment using multiple antenna ports includes an uplink channel estimation unit that estimates uplink channel states, a downlink channel estimation unit that estimates downlink channel states based on the estimated uplink channel states and channel reciprocity of uplink and downlink, a receiver unit that receives from the user equipment CSI feedback information, and a precoder generating unit that determines a precoding matrix of downlink based on Channel State Information (CSI) indicating the estimated downlink channel states and on the CSI feedback information.