Performance analysis of a reduced rank MMSE MUD for DS-CDMA

A new reduced rank multiuser detector (MUD) for DS-CDMA is presented. The algorithm is derived for the general case of an asynchronous DS-CDMA system in frequency selective multipath. The MUD solution is shown to be equivalent to a bank of parallel, single user detectors. The algorithm is implemented in reduced rank form using the correlations subtractive algorithm of the multistage Wiener filter (CSA-MWF). It is shown that the CSA-MWF implementation performs identically to the full rank solutions of MMSE MUD and meets single user, full rank performance at a substantially reduced rank for all levels of system load.