A new adaptive linear multi-stage multiuser detector for DS-CDMA systems

Conventional linear multi-user detectors (MUD) such as the decorrelating MUD and MMSE MUD require the inversion of a matrix or solution of a system of linear equations. The high complexity involved makes direct matrix inversion or direct solution of the system of linear equations difficult especially when the number of users is large. In this paper, we propose a new adaptive linear multi-stage MUD that has lower complexity. Parameters of the proposed structure can be optimized offline or update on the fly according to channel conditions. Simulation results show that the proposed MUD with a few numbers of stages almost achieves the performance of the linear MMSE MUD.