The effects of imperfect channel estimation on RBF-based multi-user DS-CDMA receivers

A chip-level RBF-based multi-user detector for the downlink of a system with similarities to the UTRA TD/CDMA system for UMTS is considered. The performance of this non-linear receiver, together with the MMSE linear receiver, is demonstrated to be sensitive to the estimation of the channel impulse response. Results are presented for estimation of this quantity both via a direct technique and also via adaptive techniques based on training using a pilot sequence, for both a stationary channel and a time-varying channel.