To provide a base station device communicating with a mobile station device by using a plurality of downlink component carriers.
A base station device communicates with a mobile station device by using a plurality of downlink component carriers. In a certain downlink component carrier included in the plurality of downlink component carriers, a plurality of user device specific search spaces monitored by the mobile station device and in which a physical downlink control channel may be arranged are set while being associated with the plurality of downlink component carriers controlled by the physical downlink control channel. The physical downlink control channel is arranged in the user device specific search space, and transmission is performed. Each of the plurality of user device specific search spaces, which are constituted by downlink control channel candidates consisting of control channel elements of the same number, is specified depending on the number of the associated downlink component carrier.
YAMADA SHOHEI
NAKAJIMA TAIICHIRO
| JP2009218813A |
Toshiaki Watanabe
Kenichi Imamura