Research Of Td-Scdma System Optimization Scheme In Heterogeneous Wireless Network

In order to make full use of the complementary advantages and improve the resource utilization rate in heterogeneous wireless networks, heterogeneous wireless networks’optimization has become the current operators’research focus. In recent years, with users’increasing demand of the data service, TD-SCDMA, WCDMA, WLAN, LTE techniques emerge which can provide high speed services. However, as TD-SCDMA and WLAN are gradually put into use, some new problems have occurred. How to optimize heterogeneous wireless networks and distribute resources reasonably need us further study.During the period of finishing my academic degree, I am fortunate enough to be a part in the project,"collaborative planning of GSM TD-SCDMA and WLAN WCDMA networks" with a Company. What I have done in this project is discussed in the paper.This paper mainly studies wireless network optimization methods based on GSM, TD-SCDMA and WLAN networks. Firstly, this paper puts forward a collaborative planning method of TD-SCDMA,GSM and WLAN heterogeneous network.It can be a solution for the current phenomenon that data service of TD network occupies3G resources in nowadays’wireless network. Secondly, this paper presents a scrambling code planning algorithm based on users’location distribution information in TD-SCDMA networks, the algorithm collects users’geographic location information and use it to recalculate scrambling codes’ correlation matrix, then it allocate the scrambling code pair which have lest correlation according to the matrix to adjacent cells, thus can reduce the inter-cells’ interference greatly. Finally, this article proposed one load balancing algorithm based on traffic prediction in heterogeneous wireless networks, the algorithm combine prediction with load balancing to avoid congestion brought by hysteresis effect and the threshold, which is used to control a networks’load and congestion rate, can be adjusted automatically,the simulation results show that this algorithm can greatly reduce the users’call blocking rate.The scrambling planning algorithm and traffic prediction method are now applied in the Beijing mobile network, which receive good feedback. The scrambling planning algorithm and load balancing algorithm both completed the patent application.