A communication is method in which communication is carried out between a base station and a mobile station by using a TDMA scheme, that is, the mobile station estimates quality of a received signal by taking a time slot as a unit, from a received signal in a time slot taken as the unit. In the case where the received signal quality estimated by taking a time slot as the unit is larger than a predetermined transmission power, the mobile station conducts transmission processing in a transmission time slot interval, with transmission power smaller in value than the predetermined transmission power by a difference value between the estimated received signal quality and the predetermined transmission power, while in the case where the received signal quality estimated by taking a time slot as the unit is smaller than the predetermined transmission power, the mobile station conducts transmission processing in a transmission time slot interval, with transmission power larger in value than the predetermined transmission power by a difference value between the predetermined transmission power and the estimated received signal quality, whereby the transmission power in each time slot interval can be properly controlled based upon the practical received signal quality.