Research On Radio Resource Allocation Technology In High-speed Railway Mobile Communication System

In order to give passengers a better travel experience,it is necessary to ensure the communication quality in the high-speed railway environment.Based on the future development trend of train communication,this thesis studies the application of LTE system in high-speed railway,mainly including LTE handover technology and uplink and downlink resource allocation mechanism.On the basis of analyzing the characteristics of high-speed railway scenes and algorithm research methods,a fast method suitable for high-speed railway LTE communication system is designed.Handover algorithm and uplink and downlink resource allocation algorithm.The optimization performance of the improved algorithm compared with the traditional algorithm is analyzed when the index parameters are set.First,the key technologies of radio resource management in LTE system under high-speed environment are introduced.Secondly,the seamless handover mechanism and the idea to be carried into the seamless handover algorithm based on the target cell are integrated to eliminate the handover interruption in the cell through delay,and the backup vehicle relay is designed to achieve the purpose of delay.It can improve the handover success rate of the target cell well.Then,the LTE uplink resource allocation algorithm of high-speed railway is studied.The uplink resource allocation is optimized based on approximate estimation,and the model is built on the basis of link proportional fair resource allocation.Comprehensive application and analysis of improved delay-based proportional fairness algorithm(M-LWDF)and improved queue-based proportional loss-based proportional fairness algorithm(M-LPL)in business operations to obtain improved proportional fairness algorithm(M-LWDF)-PF),the improved proportional fairness algorithm(M-PF)is applied to the resource allocation process of different services,and these algorithms are simulated and analyzed.Finally,the LTE downlink resource allocation algorithm of high-speed railway is studied.Based on the resource allocation mechanism of LTE itself,this paper analyzes the maximum carrier interference ratio strategy,maximum fairness strategy and proportional fairness scheduling strategy in LTE.In order to better adapt to the characteristics of high-speed railway movement,this paper also proposes a resource adaptive allocation algorithm.In order to predict the UE TTI in each case,the CQI feedback value is optimized for the RB allocation process,and a new MCS selection mechanism is proposed for the power allocation process.At the same time,it is simulated and compared with existing common resource allocation algorithms.