Combined MMSE/pcPIC multiuser detection for MC-CDMA

MC-CDMA is an attractive candidate for future mobile broadband communications because it combines the advantages of OFDM and CDMA. However, detector design for the reverse link is still an open area of research. We propose a MC-CDMA multiuser detector for frequency-selective slow fading channels. It consists of a linear MMSE stage, followed by one non-linear parallel interference cancellation stage, which acts on a per-carrier basis. Furthermore, to take care of its initialisation, we devised a training-based fully adaptive version of the detector, that does not require any a-priori information. The MMSE-pcPIC detector outperforms a classical MMSE detector by 7 dB for a BER of 10^-2, while maintaining linear complexity in the number of active users