A mobile station includes a plurality of mobile station antennas that receive at least one independent training signal from a plurality of base station antennas, and estimates a downlink channel formed by each of a plurality of base station antennas and each of the mobile station antennas by using the at least one independent training signal. The mobile station generates a beam vector by using the downlink channel, and forms transmission beams in the plurality of mobile station antennas for transmitting a signal to an uplink.