Dual-cell HSDPA:n vaikutukset WCDMA-tukiasemaan
Warma, Henna · Aaltodoc (Aalto University) · 2009
Dual-cell high-speed downlink packet access (DC-HSDPA) is part of evolved HSPA (HSPA+) specifications in 3GGP Release 8. In DC-HSDPA the data stream to one user equipment is sent over two adjacent carriers and it doubles the peak rate of legacy HSDPA. DC-HSDPA only applies to the downlink so the uplink traffic is conveyed over one carrier. Joint scheduling, which is used for DC-HSDPA carriers, enables gain compared to the single carrier HSDPA (SC-HSDPA) because of higher multiuser diversity. DC-HSDPA can be implemented with rather minor changes in the user equipment, base station and radio network controller (RNC). This study provides an extensive description of DC-HSDPA. Ali the 3GPP specifications of DC-HSDPA are studied and the feasibility of DC-HSDPA to the base station is demonstrated. This means that the requirements for the base station are defined. DC-HSDPA is considered as an alternative for HSDPA MIMO, doubling the peak data rate of SC-HSDPA. The fundamental difference between these two technologies is that DC-HSDPA works with a single transmission antenna in the base station and in the user equipment while HSDPA MIMO requires development of multiple transmission antennas. The simulation results show that the DC-HSDPA performs as well as HSDPA MIMO and even better in poor channel conditions. Because the implementation of HSDPA MIMO is more complex compared to DC-HSDPA, the costs of implementing HSDPA MIMO are also bigger. This study provides also a quantitative performance analysis of DC-HSDPA and MIMO demonstrating the throughputs of each technology in different channel conditions. DC-HSDPA and HSDPA MIMO are also compared from the economical point of view which shows the cost difference of implementing each technology in the base station site.