Interference cancellation for space-time block-coded MC-CDMA systems over multipath fading channels

We consider a space-time block-coded multi-carrier code-division multiple access (STBC MC-CDMA) system over multipath fading channels. We first develop a model for such a system with two transmit and one or two receive antennas. Different receiver algorithms are proposed, including maximum ratio combining (MRC), minimum mean square error (MMSE), parallel interference cancellation (PIC), and interference cancellation based on the expectation-maximization (EM) algorithm. Performance of these different receivers is illustrated by numerical results in a system with 5 MHz bandwidth at 2.5 GHz over some ITU channel models. STBC MC-CDMA with two-transmit and one-receive antennas has better performance than the single-input single-output (SISO) MC-CDMA system. The performance can be further improved by adding an extra receive antenna.