Research Of High Speed Downlink Packet Access In The WCDMA

It's one of the hot points in the world that the research and commercial test on 3G mobile telecommunication system. WCDMA is one of the main aspect of 3G standards. With the higher demand for transmission rate, more and more people paid close attention to mobile telecommunication system Beyond 3G.HSDPA (High Speed Downlink Packet Access) is an update for WCDMA which has good performance which could offer similar performance as WLAN, such as high mobility and covering power. It offers higher data transmission speed, high capacity and better competitive advantage comparing with fixed wireless wideband service supplier. So it's significant to investigate the techniques and implement methods of HSDPA. It's presented the technique of HSDPA downlink which based on WCDMA in this paper.In this paper, it's introduced the development of mobile communication, the necessity of HSDPA research to fulfill the demand of market in commercial test of present 3G and the evolution of HSDPA. It's discussed some key techniques of HSDPA, which includes AMC (adaptive modulation and coding), HARQ (Hybrid Automatic Repeat reQuest) and fast scheduling. It's presented the analysis of channel coding and physical layer properties for HSDPA, comparison between HSDPA and R99, simulation of HSDPA. It's presented the analysis of problem existing in HSDPA technique and a improved plan. It's comparison between HSDPA and R99.