A base station device includes: a control signal generator that generates a signal of control data including items corresponding to the type of sub-frames to be allocated; a scheduling information signal generator that generates a signal of scheduling information indicating a sub-frame to be a first sub-frame among sub-frames specified by first-type sub-frame candidate information; and a multiplexer that allocates the signal of the control data to the first-type and second-type sub-frames, and allocates the signal of the scheduling information to the first-type sub-frame. A mobile station device includes: a frame-type determining unit that determines the type of each of received sub-frames based on the first-type sub-frame candidate information and the scheduling information; and a control data detector that detects, for each sub-frame, the control data including the items corresponding to the type indicated by the result of the determination by the frame-type determining unit. Accordingly, the processing load on reception of control data is reduced.