Patent ID: 7123597

Claim:
A transmit power control method in a Code Division Multiple Access (CDMA) mobile communication system during a selection/synthesis processing in a Radio Network Controller (RNC) of up receive signals from each of base transceiver stations (BTSs) connected thereto, said method comprising: a checking step of checking whether one or BTSs are connected to a specific mobile station; a calculating step of, when a result of the checking step shows that two or more BTSs are connected, using a predetermined selection criterion for selecting CH (channel) receive SIRs (Signal to Interference Ratios) corresponding to certain ones of the connected BTSs, and making a calculation by using values of the selected SIRs; a reference value changing step of changing a value of a reference value Sref according to a result of the calculation; an upper limit setting step of, when the result of the checking step shows that only one BTS is connected, setting the reference value Sref to an upper limit; and a reporting step of reporting the changed reference value Sref to all the connected BTSs, wherein the reference value Sref is decided in the RNC in response to a variation in a selection/synthesis gain due to an increase or a decrease of the number of connected BTSs.