A base station (eNodeB) performing a radio communication with a user equipment (UE) includes: a transmission format determining unit (16) configured to determine a transmission format of a downlink data channel not to be associated by a control channel, based on a downlink reception signal quality measured by the user equipment; a notification unit (18) configured to notify, to the user equipment, the transmission format determined by the transmission format determining unit; a transmission power controlling unit (19) configured to control a transmission power of the downlink data channel; and a transmitting unit (18) configured to transmit downlink data to the user equipment via the downlink data channel, by using the transmission format determined by the transmission format determining unit.