The present invention is designed to reduce the increase in the amount of the calculation process in a mobile station and the amount of CSI feedback data, and also prevent the amount of overall system capacity from decreasing. This radio communication system (1) has a radio base station (200) which can form a plurality of beams that are vertically sectorized. The radio base station (200), using an array antenna (10), forms at least the first beam that is directed to the cell edge side and a second beam that is directed to the cell center side, in parallel. A mobile station (100) measures channel quality by extracting reference signals from each of the first beam and the second beam, generates a communication quality feedback signal including channel quality measured from at least one of the beams, and feeds this back to the radio base station (200) via the uplink.