| In the next-generation mobile communication,a dual-layer network architecture with decoupled control and user(C/U)planes will be applied in the 5G high-speed rail wireless communication system to improve data transfer rate and expand system capacity while ensuring basic cell coverage and reliable transmission of signaling.However,considering the high speed of the high-speed rail and the complex wireless environment,5G wireless communication of the high-speed rail will face great challenges,especially the performance of train handover will be greatly affected,such as more frequent handovers due to smaller coverage of small base stations,and more complex handover between adjacent macro cells because not only handover between macro base stations but also handover between small base stations should both be completed,and so on.Therefore,this paper conducts in-depth research on the channel model,network architecture,and cell handover algorithm of 5G high-speed rail wireless communication system with C/U-plane split network,and proposes two new handover schemes,which are intra-macro cell handover scheme based on the running speed of train and inter-macro cell handover scheme based on Coordinated Multi-Point(CoMP)technology.The intra-macro cell handover scheme uses the concept of train movement status classification and merges adjacent small cells to reduce unnecessary handovers and signaling overhead and improve handover performance.The inter-macro cell handover scheme combines bi-casting technology and CoMP technology to realize the connection before the handover,and simplifies the condition of trigger decision,so that the handover can be more timely and easier to succeed,and communication interruption is less.In addition,the dual antenna configuration is used on the top of the train to gain additional space diversity gain,which can further enhance the quality of communication signals.Finally,this paper simulates the two proposed handover schemes respectively.The simulations prove that the proposed two handover schemes can achieve the expected results,enhance the communication quality of the train,reduce the probability of communication interruption,and improve the handover performance of 5G high-speed rail wireless communication system with C/U-plane split network. |
