Research On Multi-Carrier HSPA

With more diverse services and enhanced capability of user equipment, it has been seen an increasing demand for higer data rates. The HSPA evolution (HSPA+) can not meet the demand any more. Since HSPA+has already introduced several enhanced features such as MIMO and high order modulation to improve the spectral efficiency, it is prefered to further improve the peak data rates by increasing the system bandwidth. In order to further improve the peak data rate and user throughput of HSPA+network, dual-carrier HSDPA is introduced in 3GPP Rel-8. The dual carrier approach can offer higher resource utilization and reduce the impact of frequency selectivity, which allows users with poor channel conditions to achieve better performance. Similarly, in order to achieve higher uplink data rates, dual-carrier HSUPA is included in 3GPP Rel-9. As an enhanced feature, MIMO is applied to dual-carrier HSDPA in 3GPP Rel-9. For affordability of mobile broadband services, (3,4) carrier HSDPA is introduced in 3GPP Rel-10.This paper mainly researches on the system design of multi-carrier HSPA, including CQI design and carrier activation/de-activation for dual-carrier HSDPA, power allocation and control for dual-carrier HSUPA, carrier activation/de-activation and HS-DPCCH design for (3,4) carrier HSDPA. In addition, this paper evaluates the performance benefit of multi-carrier HSPA system including dual-carrier HSDPA with MIMO and (3,4) carrier HSDPA. The simulation results show that multi-carrier HSPA can bring substancial gain in sector throughput as compared to the single carrier HSPA. For example, with 6 users in each sector,3 carrier HSDPA can achieve 50% gain in sector throughput over the single carrier HSDPA with 3 available downlink carriers. This paper also introduces soft frequency reuse technology into multi-carrier HSDPA system and evaluates its performance. Finally the perspective of future evolution of multi-carrier HSPA is presented.