Spreading sections of the base station spread the respective distributed data using mutually orthogonal spreading codes and are transmitted from antennas. Despreading sections of the mobile station despread the received signals using the same spreading codes as those used at the base station. Demodulation sections demodulate the despread signals. Received signal power measuring sections measure their received signal powers from the demodulation result. A received signal power combination section combines the measured received signal powers and a transmit power control section controls transmission power based on the combined received signal power. When carrying out diversity reception through a plurality of antennas at the base station, transmit power control errors are suppressed to a small level at the mobile station.