Patent ID: 8743841

Claim:
A mobile station apparatus in a mobile communication system comprising a base station apparatus and the mobile station apparatus, the mobile station apparatus comprising: a transmission unit configured to transmit periodically, to the base station apparatus, a first pre-coding indicator using a periodic feedback scheme that uses a physical uplink control channel, the transmission unit being further configured to transmit, to the base station apparatus, second pre-coding indicators using an aperiodic feedback scheme that uses a physical uplink shared channel; and a reception unit configured to receive, from the base station apparatus, a downlink signal and a pre-coder confirmation, the downlink signal having been pre-coded using pre-coding information indicated by the transmitted pre-coding indicators, the pre-coder confirmation indicating whether the pre-coding information having been used to pre-code the downlink signal is indicated by the second pre-coding indicators transmitted using the aperiodic feedback scheme that uses the physical uplink shared channel.