A base station device including: a transmitter configured to transmit a transport block that includes a plurality of code block groups; and a receiver configured to receive a confirmation signal which indicates that one or more code block groups of the plurality of code block groups has not been successfully received, wherein the transmitter transmits a control signal when the receiver receives the confirmation signal, and the control signal comprises first information that indicates the one or more code block groups to be retransmitted and second information that indicates data is combined with the one or more code block groups being retransmitted and earlier received one or more code block groups stored in a buffer.