Increasing mixed service uplink capacity of UMTS by smart antennas

Plans for possible business cases express the number of users in the system as a function of the service-mix and system loading. In this paper, the increase of mixed service capacity of UMTS by smart antennas is investigated. System capacity for mixed traffic in the uplink of the FDD mode (Wideband CDMA) is analyzed. 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. The maximum achievable effective throughput is found as a function of both the service mix and the system loading.