Mobile communication system, base station apparatus, mobile station apparatus, and mobile communication method

A mobile station apparatus that communicates with a base station apparatus using a plurality of component carriers, comprising:

• a portion that transmits, to the base station apparatus, control information on HARQ using either one of a first physical uplink control channel resource corresponding to a resource of a first physical downlink control channel and a second physical uplink control channel resource corresponding to a resource of a second physical downlink control channel, when the first physical downlink control channel for indicating transmission of a physical downlink shared channel on a specific downlink component carrier and the second physical downlink control channel for indicating transmission of a physical downlink shared channel on a downlink component carrier different from the specific downlink component carrier are received, from the base station apparatus, in a sub frame on the specific downlink component carrier, wherein
• the first physical uplink control channel resource and the second physical uplink control channel resource are mapped on a single uplink component carrier that corresponds to the specific downlink component carrier.

A communication method of a base station apparatus that communicates with a mobile station apparatus using a plurality of component carriers, comprising:

• transmitting, to the mobile station apparatus, a first physical downlink control channel for indicating transmission of a physical downlink shared channel on a specific downlink component carrier and a second physical downlink control channel for indicating transmission of a physical downlink shared channel on a downlink component carrier different from the specific downlink component carrier, in a sub frame on the specific downlink component carrier,
• receiving, from the mobile station apparatus, control information on HARQ using either one of a first physical uplink control channel resource corresponding to a resource of the first physical downlink control channel and a second physical uplink control channel resource corresponding to a resource of the second physical downlink control channel, when the mobile station apparatus receives the first physical downlink control channel and the second physical downlink control channel in a sub frame on the specific downlink component carrier, wherein
• the first physical uplink control channel resource and the second physical uplink control channel resource are mapped on a single uplink component carrier that corresponds to the specific downlink component carrier.

A communication method of a mobile station apparatus that communicates with a base station apparatus using a plurality of component carriers, comprising:

• transmitting, to the base station apparatus, control information on HARQ using either one of a first physical uplink control channel resource corresponding to a resource of the first physical downlink control channel and a second physical uplink control channel resource corresponding to a resource of the second physical downlink control channel, when the first physical downlink control channel for indicating transmission of a physical downlink shared channel on a specific downlink component carrier and the second physical downlink control channel for indicating transmission of the physical downlink shared channel on a downlink component carrier different from the specific downlink component carrier are received, from the base station apparatus, in a sub frame on the specific downlink component carrier,
• wherein
• the first physical uplink control channel resource and the second physical uplink control channel resource are mapped on a single uplink component carrier that corresponds to the specific downlink component carrier.