Research On Multi-service Coexistence Resource Scheduling Algorithm For Next Generation High Speed Rail Mobile Communication System

The rapid development of high-speed rail in recent years has made the way of transportation more convenient,while the development of high-speed rail wireless communications has been somewhat slow.With the increase in the speed of high-speed rail and the increase in transmission bandwidth requirements,the current GSM-R system used by railways has been difficult to meet user communication needs.The maturity of the LTE system technology makes the LTE-R system a candidate for the next-generation railway communication system.Although the LTE-R system can meet the general communication needs of users,the resource scheduling algorithm still needs to be improved in the case of multi-service coexistence.The multi-service coexistence in the current high-speed rail scenario mainly refers to the co-existence of high-speed rail private network services,that is,the GSM-R system provides services for high-speed rail private network services.Since the LTE-R system replaces the GSM-R system to become a dedicated railway communication system,it has become a consensus in the industry.Therefore,the resource scheduling problem when the high-speed railway private network coexists under the LTE-R system is worth studying.In the high-speed rail scenario,the service types include both high-speed rail private network services and public network user services.The safe and reliable transmission of high-speed rail private network services is closely related to driving safety.Therefore,how to allocate resources for high-speed rail private network services in the high-speed rail private network scenario has become a problem that needs to be solved to ensure the safety of railway communications.At the same time,with the increase of broadband services for public network users,the requirements for communication quality of public network users in high-speed rail scenarios have increased,and the problem of scarcity of frequency band resources has become increasingly prominent.The current GSM-R system only provides services for high-speed rail private network services,and public network users access the LTE public network.How to allocate resources for public network user services more reasonably under the condition of poor spectrum resources has become an urgent problem to be solved.(1)This article first studies the multi-service coexistence resource scheduling algorithm based on the LTE-R system.Several resource scheduling algorithms commonly used in current LTE-R systems.Regarding the existing problems such as transmission time extension and large packet loss rate in existing algorithms,this paper proposes a differentiated service transmission resource scheduling based on QCI priority for the resource scheduling problem of private network multi-service transmission in the LTE-R system algorithm.The algorithm first divides the service into real-time train control service and non-real-time train control service according to whether the train control service is sensitive to delay,and performs group scheduling for two types of services.For real-time services,the QCI priority parameter is introduced based on the maximum weighted delay algorithm,and real-time train control services are given different QCI priorities according to the transmission priority;for non-real-time train control services,CQI is introduced based on the proportional fair algorithm priority.Simulation results show that the algorithm guarantees the throughput and transmission delay performance of non-real-time services while ensuring the performance of real-time service transmission.(2)This paper then studies the resource scheduling algorithm when the LTE-R system replaces the GSM-R system and the high-speed rail private network service and the public network service coexist based on the coexistence of the LTE system and the LTE-R system.In response to the problem of insufficient bandwidth resources for public network users,this paper proposes an LTE-R radio access network(LTE-R Radio Access Network,RAN)sharing solution.Public network users can access LTE-R network sharing services.Aiming at the problem of co-frequency interference in the LTE-R system and the LTE system sharing the same frequency band,a coordinated multipoint(Co MP)scheme is proposed.When the base station provides resource blocks to the user,the silent processing of the resource blocks corresponding to the interfering base station is not Participate in resource allocation.At the same time,the coexistence of the LTE-R system and the LTE system is divided into five main scenarios,and corresponding resource scheduling algorithms are proposed in each scenario to always ensure the communication needs of high-speed rail private network user services.The simulation results show that the use of the LTE-R RAN sharing scheme and the Co MP scheme improves the user's throughput,at the same time reduces the user's interruption probability and improves the user's communication performance.This article aims to study the resource scheduling algorithm based on the coexistence of multiple services in the high-speed rail scenario,to further improve the performance of the high-speed rail communication system and ensure the user's communication needs.