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 th is paper a comparative performance evaluation for space-only and space-time processing techniques for different channel models is done. We study the i mpact of flat fading and spatio-temporal channel models. The results are ex pressed in terms of multiple-access noise rise and effective data throughpu t, which are derived by a stationary system simulator Smart-antennas provid e a clear advantage in mixed rate traffic services in comparison to non-ada ptive antennas. The system capacity can be enhanced by a factor of 2.5 or h igher depending on the multi-service mix. In urban environments, the estima ted capacity of both conventional and smart-antenna systems is lower-bounde d by the capacity obtained under the flat fading assumption. The maximum ac hievable effective throughput is found as a function of both the service mi x and the system loading.