A wireless receiver measures a reception parameter while scanning multiple pieces of reception directivity for an interval during which a signal is not transmitted from a wireless transmitter. The wireless transmitter transmits a signal while scanning multiple pieces of transmission directivity, and the wireless receives measures a reception parameter relating to reception of the signal and determines k pieces of transmission directivity that correspond to high-ranking k results, respectively, of the measurement that have a great reception parameter. The wireless transmitter forms any transmission directivity and transmits a signal, and the wireless receives measures a reception parameter while scanning M pieces of reception directivity and determines reception directivity that is to be used for data communication.