Reduced complexity and improved performance receiver for downlink MIMO MC-CDMA systems

In this paper a low complexity MIMO MC-CDMA receiver is proposed. We investigate the receiver performance and complexity in the case of despreading multicarrier code division multiple access signals (MC-CDMA) prior to V-BLAST detection in multiple input multiple output systems (MIMO). The proposed structure shows that for iterative detection, despreading before detection (DBD) reduces the effect of multiple access interference (MAI), and the reported results demonstrate improved bit error rate (BER) performance and user capacity of the system over despreading after detection (DAD). Furthermore, DBD results in reduced system complexity. The performance of both detectors is evaluated using computer simulations for a frequency selective slow Rayleigh fading channel.