In step 5a, a mobile-station measures a reception level and an interference level with the other base-stations, for a base-station considered as a communication partner. In step 5b, the mobile-station transmits a measurement result obtained in step 5a as control information to the base-station considered as the communication partner. In step 5c, the base-station determines a transmission format in a transmission format candidate group used for the transmission to the mobile-station, on the basis of the control information, etc. If the base-station discriminates that an area where the mobile-station considered as the transmission destination is located has a great influence since an interference level indicated by the control information received from the mobile-station exceeds a preset threshold value, the base-station determines use of a transmission format in which repetition is executed at more than two times after executing interleaving resistant to the interference, in the transmission format candidate group.