| 摘要 |
PROBLEM TO BE SOLVED: To provide a wireless communication system in which a mobile station device and a base station device perform communication with each other by using a plurality of downlink component carriers, wherein PUSCH retransmission is efficiently controlled.SOLUTION: When it is determined in step S100 that the downlink component carriers for receiving PHICH are not activated, the mobile station device does not receive the PHICH, but sets ACK as HARQ feedback (step S102). If the downlink component carriers are not present in the activated carriers, the mobile station device sets the ACK in step S102, and then, determines that the uplink grant is not detected in step S103, determines that the ACK is set in the HARQ feedback in step S105, and does not transmit the PUSCH and retains the contents of an HARQ buffer corresponding to an HARQ process in step S107. |
