Interference between users in an MU-MIMO system is minimized by effective precoding, without increasing an overhead of control data. In a wireless communication system in which multiplex communication is possible between multiple UE1, UE2, and BS, a channel estimation and precoding selection unit 539 in BS estimates channels from the respective UE1, UE2 to the BS, determines a precoding matrix P from a projection matrix to make the two channel response matrices orthogonal or nearly orthogonal, and feeds back the precoding matrix P to UE2, and executes precoding on only UE2 of the two. A precoding unit 524 in the UE2 employs the precoding matrix P that has been notified to perform precoding of a data stream, and sends the precoded data stream to the BS.