PURPOSE: To maintain a good call quality and, simultaneously, to reduce a power consumption at the time of transmitting a moving body by controlling the optimum transmitting output of the moving body or a base station based on a mean value obtained from an receiving electric field and a fading pitch.

CONSTITUTION: A radio wave from the moving body is received by a receiver 1, and by a mean receiving electric field calculating part 2, the mean value is calculated. Based on the output of the receiver 1, the fading pitch is obtained by a fading pitch calculating part 3, and thereby, the action condition of the moving body, which is a communications opponent, is detected. Based on the mean value and fading pitch, a transmitting output deciding part 4 decides the comfortable transmitting output of the moving body. A transmitting output control signal generating part 5 generates a transmitting control signal to the moving body, and the signal is transmitted through a transmitter 6 to the moving body. As a result, the transmitting output of the transmitter at a moving body side is automatically adjusted, a receiving sensitivity at a base station side can be made optimum, and simultaneously, transmitting and receiving can be executed by a saved power.