A mobile station for performing radio communication with a radio base station, the mobile station includes an information generation section which generates information indicative of a result of error detection on a downlink signal received; and a sending section which sends the information via a physical uplink control channel, and sends uplink data via a physical uplink shared channel at a different transmission frequency from the physical uplink control channel and in a same transmission time period as the physical uplink control channel; whereby the information generation section and the sending section operate when the mobile station receives downlink scheduling information and uplink allocation grant in a same subframe.