Effects of UE capabilities on high speed downlink packet access in WCDMA systems
Hiroyuki Ishii, A. Hanaki, Y. Imamura, Shinya Tanaka, Masafumi Usuda, Takehiro Nakamura · 2005
High speed downlink packet access (HSDPA) is specified in the 3GPP to cope with the increasing demand of high-speed Internet-based multimedia services. HSDPA is based on techniques such as base station scheduling, adaptive modulation and coding, hybrid automatic repeat request, and advanced receiver design. This work presents system-level simulation results on the HSDPA performance to reveal the effects of user equipment (UE) capabilities such as the maximum number of multicodes and receive diversity. The results show that a 15- and 10-multi-code UE and the receive diversity significantly improve the cell capacity. Experiments using the HSDPA test-beds are conducted to investigate the true HSDPA performance. Furthermore, TCP/IP-level simulation results show the application-level throughput, i.e. end-user throughput, in the HSDPA system. The results indicate that reduction of the round trip time, a higher uplink data rate, and low uplink block error rate are required to achieve the high TCP-level throughput.