Research On Multi-Flow HSDPA System Performance And Key Technology

Driven by the users’demanding for higher data rate and better user experience, mobile communication technology develops further with short update time. HSPA+has been introduced as an import improvement of WCDMA system. HSPA+has some important technologies, such as MIMO, high order modulation, multi-carrier technology, etc, which all improve the system performance. Most of all, in the idle condition, the downlink peak data rate increases linearly with the number of carriers. In Release11,8-carrier technology has been introduced, and of course it will improve the system capacity and coverage further. Also, the user capacity would be improved by receiving at most eight data streams from the same cell simultaneously. However, in the practical network deployment, there are many cells that have not many carriers. There still exist many cells that only deployed single frequency. When the multi-carrier users move in these cells, their receive links cannot be used fully. Therefore, multi-flow transmission technology is introduced to improve the user’s data rate and cell coverage, which becomes a hot topic rapidly. Multi-flow transmission technology allows users to receive multiple data streams from different cells, which increases users’ throughput significantly, especially the users in the cell edge.This contribution mainly discusses multi-flow transmission technology evolution. Begin with the background of multi-flow transmission technology, and then introduce several multi-flow transmission schemes. A new resource management scheme is introduced based on multi-flow transmission technology and is verified to increase the system performance as well as user experience. This paper focuses on the technique problems caused by the introduction of multi-flow transmission, including the impact on the uplink and the downlink. In the downlink we mainly discuss the dynamic control of multi-flow transmission, continuous packet connectivity (CPC) and the mobility in MF-HSDPA. MF’s impact on uplink mainly reflects in HS-DPCCH channel, including the study of HS-DPCCH timing and the CQI format. In the end, the technology to be researched further is prospected.