USER DEVICE AND UPLINK CONTROL INFORMATION BIT WIDTH DETERMINATION METHOD

摘要

This user device, which communicates with a base station in a mobile communication system that supports downlink spatial multiplexing, is provided with: a transmission means that transmits capability information for the user device to the base station; a reception means that receives setting information from the base station; and a bit width determination means that, when the setting information is received in the form of a parameter indicating a transmission mode corresponding to downlink spatial multiplexing and of prescribed additional information, determines the rank indicator bit width on the basis of the prescribed additional information.