Space-time adaptive reduced-rank detectors for DS-CDMA based on interpolated FIR filters

A space-time adaptive reduced-rank processor for interference suppression in DS-CDMA systems is proposed based on interpolated FIR filters. The interpolated minimum mean squared error (MMSE) solution is described for a novel scheme where the interpolator is rendered adaptive and adaptive algorithms are developed for estimating the parameters of both reduced-rank receiver and interpolator. Linear and successive interference cancellation (SIC) space-time receivers with the proposed structure are investigated for mitigating multi-access interference (MAI) and intersymbol interference (ISI) in an uplink scenario. An analysis of the convergence properties of the proposed structure is carried out and simulations for typical scenarios are performed, showing the superiority of the method against previously reported ones