Analysis of closed loop power control modes in UTRA-FDD under time varying multipath channels

Fast power control is perhaps the most important aspect in a WCDMA system like UTRA-FDD. In this paper, closed loop power control procedures in UTRA-FDD are studied. A physical layer simulator, which has been implemented in the C language from the standard of the UTRA-FDD mode, has been the tool to get the results included in this research. Simulations have been made for different mobile speeds (3, 30, 50 and 120 Km/h) getting very different results. Power control gets worse quickly as the mobile speed grows. The implementation of an adaptive algorithm to predict the received power to try to improve the power control has been studied, but large improvements have not been obtained. The probability distribution of the power control error and influence of SIR estimation error have also been studied.