The Study And Implementation Of Key Technologies Based On Ip Transport Cdma2000 Base Station Baseband Processor

The third generation mobile communication system has gain much attention in recent years .The network architecture based on IP plays an important role in 3G networks. IP-based character makes the system more flexible, expandable, and cost-benefit.The CMT mobile communication system developed by NDSC is a project that associates the cdma2000 wireless technology with the IP transmission technology. CMT system is a part of the National's 3G-development project.Wireless Access Unit is an indispensable component in CMT system that takes in charge of the communication with the mobile station. This paper focuses on the base band process based on the core chip-CSM5000 and sheds light on some key technologies.Synchronization is a key character of cdma2000 system. This paper makes researches in the timing synchronization. The improvement in cdma2000 about access technique is also talked about in the paper because the traditional IS-95's assessment cannot meet the greatly increased demand for data transmission (such as short message) any longer.Dedicate channels are used to transfer user's traffic and signal. It's efficiency and stability is of great importance to the whole base band systems's processing ability. This paper put forwards useful methods on how to quicken the reverse channel acquirement and on how to set the initial transmit power. It settled the problem of transmission delay caused by IP network. Many techniques are used in the software design.As a code division system, the management of Walsh code resource is very important for the capability of the system. According to the using model in cdma2000,this article gives an improved Walsh code allocation algorithm which is dynamic and efficient. This algorithm uses the computer memory management method for reference and shows a perfect combination of computer science and communication science. This algorithm has gained much laudatory comments.