Provided is a mobile station capable of effectively reporting control information in RACH. In the mobile station, a signature selection unit (111) selects one of different code sequences as a signature according to inputted control information and a modulation unit (112) modulates a signature (code sequence). In a table provided in the signature selection unit (111), for control information '000', CAZAC sequence #1 as a basic code sequence and a derived code sequence of shifts 0 to 7 derived from the CAZAC sequence #1 are set while being correlated to each other. The derived code sequence of shifts 0 to 7 of the CAZAC sequence #1 respectively correspond to signatures #1 to #8. Moreover, for control information '001', CAZAC sequence #2 as a basic code sequence and a derived code sequence of shifts 0 to 7 derived from CAZAC sequence #2 are set while being correlated to each other. The derived code sequence of shifts 0 to 7 of the CAZAC sequence #2 respectively correspond to the signatures #9 to #16.