A mobile user terminal, which transmits downlink quality information indicating downlink channel quality and an uplink pilot signal to a base station, in which a carrier frequency used for transmitting the downlink quality information and a carrier frequency used for transmitting the uplink pilot signal are selectable respectively from among a plurality of carrier frequencies assigned to a mobile user terminal, a mobile user terminal comprising of a radio transmitting unit, which transmits said downlink quality information and said uplink pilot signal by using the same carrier frequency among a plurality of carrier frequencies or by using adjacent carrier frequencies among a plurality of carrier frequencies.