Chip Level Adaptive Equalization for Satellite High Speed Downlink Packet Access (S-HSDPA)
Azızul Azizan, Atta Ul Quddus, B.G. Evans · 25th AIAA International Communications Satellite Systems Conference (organized by APSCC) · 2007
S-HSDPA is a concept that modifies terrestrial HSDPA in order to increase the throughput for S-UMTS and SDMB systems. In this paper, we consider S-HSDPA transmitted signals from GEO satellites via the IMR channel to the UE. The IMR channel is a highly dispersive multipath fading channel, and for this reason, the orthogonality between spreading signatures is lost, resulting in a reduction of average achievable throughput. In order to improve the performance, we investigate the performance of a linear chip level equalizer introduced at the receiver side. The results presented here highlight the advantage of the low complexity CPICH NLMS equalizer in comparison to a conventional RAKE receiver. The CPICH NLMS equalizer successfully increases the throughput of the SHSDPA by retaining the signal orthogonality with a relatively small increase in computational complexity.