LTE Handover Algorithmand Procedure For High Speed Railway Scenario

Handover technique, as one of the key techniques in TD-LTE mobile communication system andits algorithm has a great influence on the inter-cell mobile communication. In the high-speed mobile environment with the speed of350km/h, traditional handover algorithm can not meet the quality of service requirements of the system. Therefore, in the TD-LTE mobile communication system, newoptimized handover algorithms are needed for high-speed mobile environment.In this paper, the optimized handover algorithm based on A3incident and the handover algorithms based on the location information are mainly discussed. The main contents of the paper are as follows:Do deeply understandingand description of the LTE system architecture. Research on the system signaling processes of handover, based on the LTE protocol and LTE-SIM protocol framework software. Build a handover algorithm simulation platform and add the scenes of the high-speed railway, network topology module, mobility module,3rd layer filter modules, handover algorithm module in it. Based on these, the simulation parameters are configured. Do analyze of traditional handover algorithm based on the A3incident, and do the simulation of it on the simulation platform, including the packet dropping rate, the radio link failure rate, the ping-pong effect. Based on this traditional algorithm, anew algorithm is proposed, in which statistical threshold is used to replace the time to trigger, which can reduce the probability of radio link failureand improve the system performance. On the simulation platformthe performance of the optimized algorithm is simulated and compared with the performance of traditional handover algorithm. Several advantages of the new algorithm are summarized. This handover algorithm has a better performance in high-speed scene.We propose a LTE fixed point switching algorithm in high-speed railway environment, measuring parameters by the user equipment are the reference signal received power (RSRP) and block error rate target cell (BLER).Performance of a fixed point handover Mechanism between LTE eNodeB is analyzed by comparing with A3algorithm.The simulation results show, either mountain environment or plain environment in high-speed mobile environment, fixed point algorithm has better performance than A3algorithm.