One Multiuser Detection Technology With Global Optimality Algorithm

The presence of multiple access interference (MAI) constitutes a major impediment to reliable code-division multiple-access (CDMA) communications, particularly in the case that near/far effect exits. Multiuser detection (MUD for short) is an efficient technique to mitigate the effect of MAI by making the full use of multiuser information.In this paper, we introduce conventional multiuser detectors for synchronous CDMA and analyses their performances and strongpoints and shortcomings. Then we present the performance guideline of MUD.Based on Global-Optimality algorithm and optimal MUD (Multiuser detection), we propose a MUD pre-processor. And we prove it in logic and do siluation using Matlab as a doublecheck. Then we use this pre-processor in both DS-CDMA system and STBC-CDMA, we figure out the performance distribution and compare it with that using conventional MUD and that without MUD, it indicates a big improvement in performance.This paper is to do research on Global Optimality algorithm and embed it into MUD as a new pre-processor on both STBC-CDMA and DS-CDMA system. Compared this new MUD with conventional MUD and that with no MUD, we make a simulation on performance and computing time. The simulation report indicates that, with the users increasing this pre-processor becomes robust and has a better performance. But it also indicates that this good outcoming comes with a timing cost. But the computing time is ignorale especially in STBC-CDMA system, so it holds considerable promise in scientific research.