MOBILE COMMUNICATION SYSTEM, BASE STATION, AND USER TERMINAL

摘要

A mobile communication system according to the present invention comprises: a base station; and a user terminal configured to perform uplink communication via a plurality of carriers including a first carrier. The user terminal comprises: a reception unit configured to receive change information for changing a carrier used to transmit a physical uplink control channel to a carrier other than the first carrier from the base station performing uplink communication via at least the first carrier; and a terminal-side control unit configured to change the carrier used to transmit the physical uplink control channel to the carrier other than the first carrier based on the change information.