User apparatus and soft buffer size determination method

摘要

A user apparatus configured to perform communication with a base station in a mobile communication system that supports downlink spatial multiplexing such that the user apparatus includes a transmitter that transmits category information of the user apparatus to the base station and a receiver that receives configuration information from the base station. If the category information is a value equal to or greater than a predetermined value and if a parameter indicating a transmission mode corresponding to the downlink spatial multiplexing and predetermined additional information are received as the configuration information, a processor determines a soft buffer size used for downlink data reception processing in the user apparatus by using the total number of soft channel bits corresponding to the category information.