RADIO BASE STATION, USER TERMINAL, AND RADIO COMMUNICATION METHOD

摘要

PROBLEM TO BE SOLVED: To reduce overhead of a reference signal for CSI measurement in a high-order MIMO multiplexing technique.SOLUTION: A radio base station used in a frequency division duplex (FDD) radio communication system includes: a receiving unit for receiving a reference signal for time division duplex (TDD) channel state information measurement transmitted by a plurality of antennas included in a user terminal; a measuring unit for measuring channel state information with the use of the reference signal at a plurality of reception antennas; a generating/selecting unit for generating an optimum precoding vector from the channel state information measured at each reception antenna or for selecting an optimum precoding vector from a predefined precoding vector set; and a transmitting unit for performing MIMO multiplexing transmission of a physical downlink shared channel with the use of the precoding vector selected by the generating/selecting unit.