Bit-Interleaved Coded Modulation with Iterative Interference Suppression for Multi-Sequence Signaling Based MC-CDMA

This paper addresses an iterative receiver with joint detection and decoding for multi-carrier code division multiple access (MC-CDMA) systems employing multi-sequence signaling. A bit-interleaved coded modulation (BICM) technique, facilitating the "turbo principle" receiver through iterative processing, is utilized to maximize the frequency diversity, followed by a multi-sequence signaling set mapper with functionality of modulation in conjunction with spreading. User cross-correlations could be adversely increased due to the channel frequency selectivity and utilization of expanded signature sequences per user. To account for this ensuring performance loss, we employ a soft space-time interference cancellation receiver derived by minimum mean-squared error (MMSE) sense on a basis of per sequence plane per user to provide reliabilities of code bits. Simulation results justify our proposed approach in terms of bit error rate over a quasistatic fading channel with the number of users a significant fraction of spreading length. Performance comparison between our proposed scheme and conventional bandwidth-efficient coded MC-CDMA system is also manifested via simulations.