Abstract
This paper presents a new soft-input soft-output multistage partial parallel interference cancellation (PPIC) detector for direct-sequence code-division multiple-access (DSCDMA) systems. The proposed detector has a similar simple structure to the conventional PPIC scheme presented by Divsalar et al. A new way of reliability iterating is derived based on the single-user maximum a posteriori (MAP) criterion. At each stage, extrinsic information is extracted and then used as the apriori information for the next stage, just as the manner of powerful turbo decoding. Extensive computer simulations have shown that the proposed approach is capable of offering a good performance gain over the conventional PPIC scheme and some other well-known multiuser detectors, especially when the system load is heavy.