Spreading Sequence Assignment in WCDMA for Distributed Antenna Arrays Based on Interference Model

A new spreading sequence assignment scheme for WCDMA is proposed in this paper. It is based on a simple but exhaustive model of the interferences involved: multiple access (MAI) and inter-finger interferences (IFI) at a mobile RAKE receiver output. These interferences are mainly determined in this work by the correlation properties of the spreading sequences. The new approach assigns spreading sequences in a way that minimum interference power between active users can be achieved. Simulation results show that the new scheme outperforms natural (consecutive ordering) scheme for the typical central situation of antenna arrays in a cell, but these benefits are even higher for a configuration of distributed antenna arrays around the cell