A Study On Wireless Heterogeneous Network Location Technology And Switching Decision

With the development of mobile Internet and the rapid growth of intelligent terminals,mobile data services are showing an explosive growth momentum.In order to meet this demand,high density,high coverage of the heterogeneous network began to come out.Heterogeneous network deployment brings benefits such as improving network throughput and resource utilization,sharing Maccrcell's data services,extending coverage of the community,and challenging challenges such as frequent switching issues,inter-cell interference Problems and so on.In this thesis,based on the location information of radio resource management research,the specific work is as follows:(1)Summarizes the research background and research status of the topic: introduces the related concepts of heterogeneous networks,commonly used wireless positioning technology and wireless positioning technology performance evaluation indicators;heterogeneous network handover decision algorithm and other related technologies.(2)For the new generation of core LTE network under the traditional positioning technology there are two problems: the first is in the NLOS environment positioning accuracy is not high;the second is the number of base stations to locate the requirements.In order to solve the problem that the localization accuracy of traditional positioning technology is not high in NLOS environment,an improved single base station hybrid location algorithm is proposed based on heterogeneous network LTE/Wi-Fi.Based on the geometric model of signal transmission and the signal strength fading model,the objective function is established,and the improved PSO algorithm is used to dynamically adjust the inertia weight based on the fitness.The simulation results show that the proposed algorithm can make full use of NLOS environment information.Compared with other models,the improved algorithm is simple,the positioning accuracy is high and the stability is good.(3)Switching occurs frequently with the movement of the UE,and the number of handoffs directly affects system performance and network QoS.Based on the LTE / LTE-A heterogeneous network,the existing switching decision algorithm is studied.It is found that there are two problems that need to be improved: the first is that most of the current switching algorithms lack the common layer switching in Femtocell,the second problem Is how to switch quickly when the UE enters the fast exit problem.In order to solve these two problems,an improved efficient switching decision algorithm is proposed based on LTE / LTE-A.It is a new handover decision algorithm based on UE speed.In this algorithm,the handover is limited according to the UE speed and a time threshold of the target cell.The simulation results show that the improved handover decision algorithm has a significant reduction in the number of switching times and the performance of the network system compared with the traditional handover decision algorithm.