Method and apparatus for public channel auto gain control

The invention discloses a method for controlling automatic gain of public channels, which judges SIR and RSCP values of public channels to determine whether the corresponding code channels transmit signals on the received time slot of the public channels, if not, the RSSI and path loss values are computed, and then compute the AGC gain value by them. The invention also discloses a device capable of executing the method. According to the method, it can greatly decrease the probability of system's failure to receive task which caused by the deviation of the AGC gain value when adopting AGC iterating algorithm to receive the public controlling channels, therefore, the system can obtain proper AGC gain value when receiving the public channels.