Performance of uplink power control during soft handover in WCDMA system

The coordination of power control and soft handover is an important mechanism for interference-reduction to increase the system capacity. The performance of SIR-based closed-loop power control (CLPC) for the WCDMA UTRA-FDD uplink has been evaluated, dealing with the special requirements set by using these algorithms when the mobile station is connected to more than one base station during soft handover. The simulation has been developed using a simulation tool written in MATLAB. Two power control algorithms, PCA1 and PCA2, specified by the 3^rd generation partnership project (3GPP) have been simulated and compared in a vehicular environment. The performance metrics in comparing these two power control algorithms are the power control error (PCE), which is the difference between the received E_b/N_O and the E_b/N_O target, and the average MS transmitted power. Simulation results indicate that PCA1 outperforms PCA2 for the range of speeds considered. Higher average mobile transmitted power and SIR are required in PCA1 to support higher data rate users.