Heterogenous Information Aided Semiblind Group MUD for MIMO MC-CDMA Systems

This paper presents an effective semiblind group multiuser detector (MUD) for uplink multiple-input multiple- output (MIMO) multi-carrier code division multiple access (MC- CDMA) systems. The MUD considered is a two-stage linear constrained minimum variance (LCMV) detector which uses heterogeneous information (both hard and soft) to enhance the interference cancellation capability. The first stage LCMV detector produces a tentative detection output, while at the second stage a bank of soft LCMV detectors successively refine the estimated interference group by group with the assistance of the heterogeneous information in the symbol detection process. In addition, to avoid the annoying ordering mechanism, a channel- strength criterion is employed to order the groups at the second stage. Conducted simulations show that the proposed MUD can drastically enhance the performance compared with previous works, especially when the hardware cost is at a premium.