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, SIR_target. A higher layer outer loop adjusts SIR_target 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, SIR_est. SIR_est 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 SIR_est.

The obtained SIR estimate SIR_est is then used by the UE to generate TPC commands according to the following rule: if SIR_est > SIR_target then the TPC command to transmit is "0", requesting a transmit power decrease, while if SIR_est < SIR_target then the TPC command to transmit is "1", requesting a transmit power increase.

When the UE is in soft handover, the UE should estimate SIR_est from the downlink signals of all cells in the active set.