Smart-Antenna Space-Time UMTS Uplink processing for system capacity enhancement

The system-level performance of Smart-Antenna Space-Time Uplink processing for the frequency division duplex (FDD) mode in UMTS is investigated. In this paper a comparative performance evaluation for space-only and space-time processing techniques for different channel models is done. We study the impact of flat fading and spatio-temporal channel models. The results are expressed in terms of multiple-access noise rise and effective data throughput, which are derived by a stationary system simulator Smart-antennas provide a clear advantage in mixed rate traffic services in comparison to non-adaptive antennas. The system capacity can be enhanced by a factor of 2.5 or higher depending on the multi-service mix. In urban environments, the estimated capacity of both conventional and smart-antenna systems is lower-bounded by the capacity obtained under the flat fading assumption. The maximum achievable effective throughput is found as a function of both the service mix and the system loading.