Infinite-length implementation of linear chip-level equalizer by blind recursive filtering for the DS-CDMA downlink

This work deals with a receiver for the DS-CDMA downlink. User signals are transmitted synchronously using orthogonal spreading codes. Multipath propagation of the transmission channel generates inter-chip interference which deteriorates performance. Linear chip-level equalization followed by a filter matched to the code of the desired user allows performance to be improved. We show that an infinite-length implementation of the linear MMSE chip-level equalizer can be achieved using two recursive filters optimized from a blind criterion. Simulation results over a multipath Rayleigh channel show that the proposed receiver outperforms the finite-length implementation of the linear MMSE receiver and the ideal RAKE receiver.