To reduce a power consumption when a base station transmits a received signal.

When the base station transmits the received signal in a transmission diversity mode by using two antennas, a level measuring circuit 12 measures the electric-field level of the received signal from one antenna of the base station, and the electric-field level of the received signal from the other antenna of the base station on the basis of a fading vector calculated by a phase estimation circuit 11. When the electric-field level of the measured received signal is compared with a prescribed threshold value, the effectiveness of the received signal from one antenna and the effectiveness of the received signal from the other antenna are judged respectively. When a control signal is issued to turn off a switch arranged between a TCXO 8 and a phase correction circuit used to phase-correct the received signal from the antenna whose effectiveness is judged to be invalid from among phase correction circuits 13, 14, the switch is turned off, and the supply of an operating clock to the corresponding phase correction circuit is stopped.