Joint interference cancellation and ML decoding scheme for a space-time coded DS-CDMA system in a multipath fading channel

A joint interference cancellation and maximum likelihood (ML) decoding scheme is proposed for a space-time coded DS-CDMA system in a multipath fading channel. Arrival time difference between multiple transmit antennas by multipaths causes not only inter-symbol interference but also multiple-access interference and inter-antenna interference between the desired signals transmitted from different antennas. To mitigate the effect of the interferences a joint algorithm for the proposed scheme is presented, in which an adaptation process for the AIC is merged in the conventional ML decoding algorithm. The performance of the proposed scheme is evaluated for the space-time coded DS-CDMA system with two transmit antennas. It is shown that the proposed scheme achieves significant performance improvement over the conventional ML decoding scheme.