The Research And Simulation Of The Performance Of WCDMA Downlink And Soft Handover

WCDMA technology has been broadly adopted as one of the important air interface standard in 3G systems. Comparing with CDMA technology, WCDMA supports higher code rate, wider carrier bandwidth. It is much more important that WCDMA has the new radio resource management method which can assure the planned coverage and improve the system capacity. Power control and soft handover are the two important algorithms in the radio resource management method.In this paper, how the different services impact on the system capacity has been analyzed in WCDMA downlink. As more, the thesis introduces how the soft handover, as the method of radio resource management, impacts on the downlink capacity. Using system simulation, the thesis has proved that when the scale of soft handover overhead in a certain range, soft handover can improve downlink capacity. At last, based on the analysis of the balanced power assignment and unbalanced power assignment, we put forward a new power assignment algorithm based on path loss. The new algorithm solves the disadvantage of the capacity improvement that the traditional algorithm does not have. It also improves the WCDMA downlink performance during the soft handover.