Novel concatenated space-time multiuser detector based on recursive constrained CMA with modulus correction

The recursive constrained constant modulus algorithm (R-CCMA) with modulus parameter correction has fast convergence rate and good steady-state performance, and is robust to ill-conditioned initialization of weight vector and modulus parameter. These distinctive properties make it very suitable for time-varying channel applications. This paper presents a novel concatenated space-time multiuser detector based on it for uplink reception in a DS-CDMA system with periodic spreading. It consists of two stages: the spatial filter bank based on block RLS despread respread directing algorithm (BRLS-DRDA) is the first, which extracts the desired signal of each delay path and suppresses interference via spatial domain filtering; the R-CCMA multiuser detector is the following stage whose task is to further suppress interference from other paths and other users with temporal domain processing. Simulations show that it has quite fast convergence rate and very good steady-state performance.