Analysis And Research Of MUD Algorithm In 3G System

The advantages of CDMA communication system in 3G are large capacity, soft capacity, soft handover, higher spectral efficiency and the ability to resist the effects of multi-path fading, and so on. In code-division multiple-access (CDMA) systems, multi-access interference (MAI) and"near-far"problems are the predominant factor. The third generation mobile communication system regards multi-user detection as an effective method to overcome MAI.This thesis puts focus on blind MUD algorithms through theory analysis and simulations based on the current MUD technologies. The main contributions of this thesis are in the following:(1) Make analysis and simulations on Signal Interference Rate (SIR), EOE in different environment of LMS algorithm, RLS algorithm and Kalman algorithm of the blind mufti-user measures. The computer simulation shows that RLS algorithm and Kalman algorithm are of great convergence performance, stable SIR and accurate tracking in timing channels, but high complexity.(2) LMS algorithm is of lower complexity but poor convergence performance. Because of the disadvantage of blind MUD LMS algorithm, author proposes an improved type of blind MUD LMS algorithm and makes analysis and simulation of its SIR and anti-interference performance. Simulation results show that the convergence performance of this algorithm is superior to LMS algorithm.