Adaptive minimum bit error rate space-time Rake receiver for the uplink of UMTS frequency division duplex mode

A novel adaptive space-time Rake receiver is proposed for UMTS frequency division duplex mode based on the adaptive minimum bit error rate (AMBER) criterion. The design of this space-time Rake receiver builds on previous results reported by Chen et al. for temporal or spatial processing, respectively. The original AMBER approach assumes short spreading sequences, i.e. they need to be invariant from symbol to symbol. Here we extend the approach to joint space-time processing and tailor the receiver specifically for a UMTS FDD system with long scrambling sequences in the uplink. The base station receiver uses a two- or four-element antenna array.