In CDMA the power control is done by an Open Loop and by a Closed Loop.
In Closed Loop the process involves both, the Base Station and the mobile.
The Base Station continuously monitors the reverse link and command the mobile to change the power up and down, very fast (1500 times/second).
Inside the mobile the gain of the PA is constant, so the power control is done at the input of the PA by the VGA (Variable Gain Amplifier).
If the Gain of the PA is not changing with Temperature and Vcc, the output power at antenna connector will follow the calibrated values.