摘要 |
In case that a base station apparatus and a mobile station apparatus use a plurality of component carriers to communicate with each other, they effectively transmit and receive HARQ control information. At least one physical downlink control channel on at least a first downlink component carrier attempts to be decoded, and, in case that one physical downlink control channel corresponding to one physical downlink shared channel transmission on a second downlink component carrier other than the first downlink component carrier is detected, the HARQ control information is transmitted to the base station apparatus using a first physical uplink control channel resource whereas, in case that one physical downlink control channel corresponding to one physical downlink shared channel transmission on the first downlink component carrier is detected, the HARQ control information is transmitted to the base station apparatus using a second physical uplink control channel resource. |