RADIO COMMUNICATION SYSTEM, RADIO COMMUNICATION DEVICE, AND RADIO COMMUNICATION METHOD

摘要

It is possible to improve the reliability of beam selection by precoding. According to a channel estimation value of a received pilot signal, a user terminal (52) selects an optimal beam (beam number b) in the next frame (t + 1) and transmits a difference D (= b - a) between the beam number "a" of the current transmission reported by the radio base station (51) and desired beam number "b" selected to be transmitted at the next transmission as a feedback signal to the radio base station (51). The radio base station (51) stores the beam number "a" reported upon the previous transmission and combines the beam number decided by the difference Dreceived upon reception of the feedback signal and the previously reported beam number "a" so as to restore the beam number "b" desired by the user terminal (52). Precoding appropriate for the beam number "b" is performed and a beam in the form of an appropriate beam number "b" is transmitted to the user terminal (52).