An MMSE-Nulling Partial-PIC Receiver for Multiuser Downlink MIMO MC-CDMA Systems

A minimum mean square error (MMSE) nulling partial parallel interference cancellation (PPIC) receiver for downlink multipleinput multiple-output (MIMO) multicarrier (MC)-CDMA systems is proposed. Our analysis shows that, for multiuser MIMO MC-CDMA systems, interference due to frequency selectivity in multipath fading channel causes detrimental effects on cancelling, thus V-BLAST receiver shows severe performance degradation. The proposed receiver with multistage processing does not produce an error floor in frequency selective fading channel environments and achieves substantial performance gains. The system performance of the proposed receiver was evaluated through computer simulations. The simulation results show that, with two stage PPIC processing, the proposed receiver achieves performance gains of 2.5–4 dB at target BER of 10−3 over the linear MMSE receiver. key words: MIMO, MC-CDMA, V-BLAST, PIC