Performance Comparison Of MIMO Multi-carrier CDMA Systems

Code Division Multiple Access (CDMA), Multicarrier modulation and Multiple input multiple output (MIMO) are three key techniques of the fourth generation mobile communication. Their combination can greatly improve system performance and fulfill the requirement of future mobile communication. In this thesis, we focus on the simulation analysis of the performance for MIMO Multicarrier CDMA uplink system.Based on the previous research of our laboratory, the dissertation discusses the structures of transmitters and receivers for three kinds of uplink multicarrier CDMA systems with array antennas, which are MC-CDMA, MC-DS-CDMA and MT-CDMA, and compares the BER performance of the three systems by simulating when the spectral efficiency is constant. Results show that MC-CDMA system with array antennas has the best performance because of frequency diversity and space diversity.Then, the dissertation discusses the structures of transmitters and receivers for three kinds of uplink multicarrier CDMA systems with V-BLAST, which are MC-CDMA, MC-DS-CDMA and MT-CDMA, and compares the BER performance of the three systems by simulating when the spectral efficiency is constant. Results show that V-BLAST MT-CDMA system can accommodate the most users because of its multi-path environments.At last, the dissertation discusses STBC MC-CDMA system and V-BLAST MC-CDMA system; and compares the BER performance of MC-CDMA systems with different STBC and V-BLAST when the spectral efficiency is constant. Since adaptive modulation has good influence on system performance, we simulates the BER performance of the above two systems with adaptive modulation. Results show that, BPSK is the most robust modulation on the category of PSK, which gives the best BER performance. It can accommodate the highest number of users while maintaining a particular BER performance than other methods. The results also show that higher order modulation formats, which are spectrally more efficient need better channel conditions than the lower order modulation schemes for a better criteria.