Effect of channel estimation error on a new pipelined multi-stage PIC detector for CDMA

We study the effect of channel estimation error on the performance of multiuser detection for downlink and uplink CDMA based on a new pipelined multi-stage parallel interference canceler. The bit error rate performance is compared among complete, partial, and ideal channel estimation. We show that the performance with ideal channel estimation approaches the single user bound for both downlink and uplink. The performance is degraded with partial channel estimation and significantly degraded with complete channel estimation as a result of channel estimation error. The degradation is more significant for the uplink due to more severe interference. Channel estimation error also harms the near-far resistance.