The purpose of the present invention is to obtain traffic-adaptive gain while mitigating inter-cell interference, in a wireless communication system in which time division duplexing (TDD) is used. In this wireless communication system, each wireless base station in a cluster uses an UL/DL configuration to communicate with user terminals. The wireless communication system is provided with: a subset selection unit which selects, from among a plurality of subsets respectively including a plurality of UL/DL configurations determined on the basis of the number of fixed subframes having a fixed transmission direction in the cluster, a subset to be used in the cluster; and an UL/DL configuration selection unit which selects, from among the plurality of UL/DL configurations included in the selected subset, an UL/DL configuration to be used to communicate with the user terminals.