Admission Control Algorithn And Handover Algorithm In TD-LTE-Hi System

Cellular penetrated into people's lives, work, entertainment and so on. With endless new application and the growing popularity of smart phones, the demand of system capacity in exponential growth, LTE - Hi arises in this background.Internet traffic is growing rapidly, carry business is becoming more and more widely, the role of mobile communication is more and more important in social life. The challenge of LTE is not enough to solve the growing needs of the business. At present, LTE - Hi is hot research direction of companies and operators. Because of high frequency have rich resources of idle spectrum, so small cells use a high frequency band (3.5 GHz). Micro base station deployment is very dense and the coverage is small, so the system is easy to generate frequent switching. The study of the handover algorithm and admission control algorithm become more complex, the purpose of this paper is to study admission control algorithm and handover algorithm in LTE-Hi system.First of all, this paper analyzes the existing admission control algorithm. It is concluded that the introduction of high density node and override the capacity enhancement, make existing admission control algorithm is no longer applicable small cells.This paper analyzes the existing admission control algorithm, in order to improve the system resource utilization, an admission control algorithm is proposed. The algorithm adopts the resource sharing model and resource preemption algorithm. The algorithm can guarantee the performance of the high priority user, make more users to access the system at the same time, and raise the resource utilization of system.Secondly, the paper analyzes the handover algorithm. In the LTE-Hi system,adopting the traditional handover algorithm can produce frequent switching,higher ping-pong switching probability, and low system performance.The paper analyzes the existing handover algorithm. According to the actual application scenarios, and taking into account the resources of the cell, a handover algorithm based on call admission is proposed. The algorithm introduces a call admission policy sets, and activates the handover algorithm in policy sets according to the use of cells resources. Due to hot spots are using 3.5 GHZ frequencies, the higher the frequency of cell has a smaller coverage, it is easy to frequent switching, the proposed handover algorithm based on the policy set can solve the problem of frequent switching.Finally, the traditional admission control algorithm, the traditional handover algorithm, the proposed admission control algorithm and handover algorithm are simulated, analysis and comparison. The proposed admission control algorithm is compared with the traditional algorithm can guarantee the performance of the high priority user, make more users to access the system at the same time. The handover algorithm is proposed in this paper compared with the traditional algorithm can effectively reduce the number of switch, make the probability of ping-pong switching fell significantly.