Performance analysis of a downlink MIMO MC-CDMA system with turbo coding and channel interleaving

In this paper, we pre-sent the multi-code minimum mean square error (MMSE) ordered successive interference canceller (OSIC) for downlink multiple input multiple output (MIMO) multi-carrier code division multiple access (MC-CDMA) systems and analyze its performance from the viewpoint of frame error rate (FER) and data throughput. It outperforms multiuser MMSE OSIC since it can cancel other antenna interference by using all known code information. We make performance comparisons between symbol interleaving before spreading and chip interleaving after spreading in the frequency domain for turbo encoded MIMO MC-CDMA systems. They demonstrate that the chip interleaving method is superior to the symbol interleaving method when the number of multipaths increases owing to the randomization effect of burst errors, and is inferior to the symbol interleaving method when the number of codes increases due to inter-code interference as SISO MC-CDMA systems. Besides, we can derive spatial diversity as well as frequency diversity from multiplexing turbo encoded data streams into transmitting antennas.