A wireless communication system 1 performs MIMO communication between a wireless base station 10 with a plurality of antennas 14 and a mobile terminal 20 with a plurality of antennas 24. A wireless base station 10 includes a selector 25 that selects, from the pairs of the antennas, one pair for which the gain is largest; the selector 25 that updates an inverse matrix of a channel matrix with respect to a group of pairs of unselected antennas to acquire inverse matrices and that selects a pair from the group on the basis of the acquire inverse matrices; and a RF switch 13 that performs communication by using the selected antennas. The selector 25 continues to update the inverse matrix and continues to select a pair from the group until a predetermined number of antennas have been selected.