A wireless communication system provides an antenna apparatus for the wireless communication system. The antenna apparatus includes a base, a plurality of Yagi-Uda antenna modules disposed in a specific arrangement, a plurality of floating metal modules correspondingly installed in upper portions of the Yagi-Uda antenna modules and selectively connected to a corresponding Yagi-Uda module among the plurality of Yagi-Uda antenna modules, a switching element for selectively switching the floating metal module and the Yagi-Uda antenna module, and a controller for controlling the Yagi-Uda antenna module to comprise a directivity in a desired direction by selectively switching the switching element.