Base station, mobile station, communication system, transmission control method, and mobile station control program

Abstract

An object of the present invention is to reduce the volume of a control signal and shorten a delay of processing in a system comprising a base station configured to transmit a pilot signal at a predetermined transmission power and a mobile station configured to transmit a preamble prior to transmission/reception of data. A mobile station comprises means for spreading the preamble with a spreading code corresponding to a reception power or a signal interference ratio of the pilot signal at the host station, based on a correspondence between the spreading code and, the reception power or the signal interference ratio of the pilot signal at the host station (power code determiner and transmitted signal converter), and means for transmitting the preamble after the spreading process (transmitter); and a base station comprises means for determining a transmission power or a downlink transmission rate for a signal directed to the mobile station, according to the spreading code of the preamble received from the mobile station, based on the correspondence between the spreading code, and the reception power or the signal interference ratio of the pilot signal at the mobile station (spreading code measuring part, estimator, and transmission rate determiner).