Time-Frequency Spread CDMA System And The Multi-user Detection Technology

The key technology of next generation communication system is researchedwidely. And the multicarrier CDMA system which combined OFDM technology andCDMA technology can provide more high transmission rate to users while using lessspectrum. But Doppler Effect is one of the obstacles that limit the capacity andperformance of CDMA system.This article propose a time-frequency spread CDMA system which every user usea frequency spread code and a group of time spread codes. It can get more processgain and become robust to inter-carrier interference. A receiver system includingmulti-user detection is proposed. Matlab is used to simulate spreading communicationand multi-user detection. In the end of this paper several simulation curve are used todemonstrate validity of proposed system. Simulation experiment results indicate thisproposed system can provid much better performance.