Research On Radio Resource Management In Urban Rail Transit Communication System Based On LTE-M And 5G Hybrid Networking

In recent years,the Fully Automatic Operation lines of urban rail transit have shown an accelerated growth trend,and higher requirements have been placed on the vehicleground communication system of urban rail transit.At the same time,due to the needs of anti-terrorism and security in the new era,the vehicle-to-ground communication system is required to provide greater bandwidth and transmit more information such as video surveillance.At present,the long term evolution for metro(LTE-M)vehicle-ground communication system,which has the advantages of strong anti-interference ability,support for fast movement,and flexible resource scheduling,has become the first choice for urban rail transit wireless communication systems.At the same time,the 5G communication system has been standardized and has been commercialized on a large scale on the public network.How to introduce 5G technology into the urban rail transit system has become a hot topic for related industries and enterprises.The characteristics of the different services are analyzed and how to set up a future urban rail transit vehicle-to-ground communication system are proposed in the thesis,which are based on the urban rail transit wireless communication scenarios.And location and soft frequency reuse based power control algorithm together with radio resource scheduling schemes are studied to improve the Qo S performance.The main work of this thesis is summarized as follows:(1)The network architectures of LTE-M and 5G-based urban rail transit vehicle-toground communication systems are described,and the current research status of mobile cellular networks,especially radio resource management based on soft frequency reuse,and the RAN slicing and slicing of 5G networks,together with the esearch status of core network slice management are introduced.(2)In view of the current development of urban rail transit vehicle-to-ground communication system and 5G,a future urban rail transit vehicle-to-ground communication architecture is proposed in which LTE-M carries communication based train control(CBTC)and other safe production services,and 5G communication system carries video surveillance services.(3)For the LTE-M vehicle-to-ground communication system,in view of the small number of users in the cell and the availability of train positioning,an uplink power control algorithm and radio resource scheduling scheme based on location and soft frequency reuse are proposed.Simulation results show that this method can effectively improve the throughput of the train access unit(TAU)in the cell.(4)In view of the future scenario where subway 5G terminals and public network terminals coexist,based on the key technology of network slicing,a slice admission control algorithm is designed to solve the problem of resource allocation among different types of tenants.Simulation analysis shows that the algorithm can autonomously learn the best admission strategy while ensuring service transmission requirements.With the goal of maximizing resource utilization,combined with the results of admission control algorithms,an adaptive resource management algorithm based on the deep deterministic policy gradient(DDPG)is proposed,and the effectiveness of the algorithm is verified by simulations from four indicators such as throughput.