Parallel Interference Cancellation for CDMA Systems

This paper presents analysis of a multistage parallel interference canceller receiver for a synchronous multiuser CDMA system. At every stage, new estimates of the multiple access interference are formed from innnitely soft decisions for the users' data. These new estimates are then used to cancel multiple access interference and form new decision statistics for the users' data. We show that in limit, when the number of stages increases innnitely, this receiver has the performance of a decorrelating detector. For an arbitrary nite number of stages, closed form expressions for the probability of error and the asymptotic multiuser eeciency of this receiver are presented and evaluated for performance comparisons with the conventional and decorrelating detectors.