Patent ID: 7218950

Claim:
A base station configured to perform radio communication based on code division multiplexing with a mobile station which transmits a preamble prior to a start of transmission/reception of data, and to transmit a pilot signal at a predetermined transmission power to the mobile station, the base station comprising: preamble receiving means for receiving the preamble spread with a spreading code from the mobile station; correspondence storing means storing any one of correspondence information between the spreading code used for the preamble and, the reception power or the signal interference ratio of the pilot signal at the mobile station, correspondence information between the spreading code and the preamble transmission power of the mobile station, and correspondence information between the spreading code and the combination of the reception power or the signal interference ratio of the pilot signal at the mobile station with the preamble transmission power of the mobile station; and determining means for determining at least one of a transmission power and a downlink transmission rate for a signal directed to the mobile station, and an uplink transmission rate for transmission of information from the mobile station, based on at least the spreading code.