B.2 Example of implementation in the UE
25.2143GPPPhysical layer procedures (FDD)Release 17TS
The downlink inner-loop power control adjusts the network transmit power in order to keep the received downlink SIR at a given SIR target, SIRtarget. A higher layer outer loop adjusts SIRtarget independently for each connection.
The UE should estimate the received downlink DPCCH/DPDCH power of the connection to be power controlled. Simultaneously, the UE should estimate the received interference and calculate the signal-to-interference ratio, SIRest. SIRest can be calculated as RSCP/ISCP, where RSCP refers to the received signal code power on one code and ISCP refers to the non-orthogonal interference signal code power of the received signal on one code. Note that due to the specific SIR target offsets described in [5] that can be applied during compressed frames, the spreading factor shall not be considered in the calculation of SIRest.
The obtained SIR estimate SIRest is then used by the UE to generate TPC commands according to the following rule: if SIRest > SIRtarget then the TPC command to transmit is "0", requesting a transmit power decrease, while if SIRest < SIRtarget then the TPC command to transmit is "1", requesting a transmit power increase.
When the UE is in soft handover, the UE should estimate SIRest from the downlink signals of all cells in the active set.