MOBILE COMMUNICATION SYSTEM

摘要

Provided is a mobile station capable of suppressing a radio resource use amount by a RACH signal and increasing the use efficiency of the radio resource. The mobile station (100) includes: a signature selection unit (109) for selecting one of the signatures at random from a plurality of signatures of different patterns; a modulation unit (110) for modulating the signature; a margin calculation unit (111) for calculating a difference between a maximum transmission power which can be used by the mobile station (100) and a transmission power of a preamble unit, i.e., a transmission power margin, and generating a report signal indicating the transmission power margin; a modulation unit (112) for modulating the report signal; a multiplexing unit (113) for multiplexing the signature with the report signal in the preamble unit; and a transmission power control unit (114) for controlling the transmission power of the preamble unit containing the multiplexed signal to a transmission power decided by a transmission power decision unit (104).