Multi-user Detection Algorithms Research And Simulink Modeling Of CDMA System

Multi-user detection as one of enhanced technology in 3G make itself receive great attentions in a series of new technique, because of its excellent ability in decreasing multiple access interference(MAI),resolving near-far effect and increasing system capacity remarkably. As is known to all, with the development of economic level and increasing requirement daily for capacity and quality of next generation communication system, we have a clear understanding that the advanced signal processing technology is a powerful engine to meet this demand. Although the majority of scholars over the study of MAI have never been interrupted, unfortunately, the balance between excellent detection ability and low complexity is not all that could be desired since the idea of multi-user detection (MUD) came into the world in 1979. Therefore, a more in-depth study on MUD is very important and more impressive when 3G era has arrived.The traditional simulation method is to use MATLAB for Multi-user detection algorithm. It could reflect the simulation results of multi-user detection algorithm well, but it can't reflect the process, not enough intuitive, not a certain degree of flexibility and program design is also more complicated. Except those it also couldn't control the simulation proceeding in real time. The Simulink dynamic simulation technology will compensate for these short-comings, it could model the modeling of the system with block diagram form, but also display the results in real time way with animation. So using Simulink dynamic simulation technology modeling of multi-user detection in theoretical research, teaching work and engineering applications have shown some advantages. The main researches and achievements include the following parts: (1) By reading a large number of joint detection information on the existing Chinese and English classical multi-user detection algorithm, study and derive the detection process. And simulate the detection performance with the traditional method of static simulation.(2) Sum up the multi-user detection algorithms on the CDMA communication system, and using Simulink dynamic simulation technique to model their detection performance.(3)Basing on a lot of research data and many times experimental simulations build a CDMA communication system library with multiple user detection Simulink model.Innovations of this paper are listed as follows:(1)A comprehensive study of multi-user detection theory and performance, based on extensive research data presents a modified decorrelation multiuser detector. And use static simulation approach to simulate its performance.(2)The traditional approach of simulating the performance of detection algorithm with CDMA system is using the static simulation way of MATLAB. This paper will use a real-time dynamic simulation modeling to model the performance of them. traditional simulation methods that exists a number of deficiencies, the new modeling methods improve Simulation program such as the readability and scalability.(3)For modeling a number of problems encountered in the practice of simulation many times, and collected a number of experiments data and modeling in the process to establish a self-built module database of CDMA multi-user detection model. It is very significant for theoretical research, teaching and engineering applications.