基于5G上下行解耦架构的服务轨道交通低轨卫星网络性能分析  

Performance Analysis of 5G Uplink and Downlink Decoupling Network Based on LEO Satellites for Rail Transportation

作　　者：朱昂立 方旭明[1] ZHU Angli;FANG Xuming(Provincial Key Lab of Information Coding&Transmission,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学信息编码与传输省重点实验室,四川成都610031

出　　处：《铁道学报》2023年第6期80-86,共7页Journal of the China Railway Society

基　　金：国家自然科学基金(62071393,U1834210);四川省应用基础研究重点项目(2020YJ0218);中央高校基本科研业务费(2682021CF019)。

摘　　要：随着通信技术的发展,卫星通信特别是低轨(LEO)卫星通信将成为下一代移动通信系统的重要组成部分。此外,随着具有全面感知、传输可靠、智能处理的智能交通通信技术的兴起,基于LEO卫星网络的智能交通通信网络能有效解决智能交通领域特别是高铁高速移动性导致的通信质量下降问题,通过卫星下行链路的大区域覆盖可减少部分链路的切换次数,提升通信链路的可靠性,同时弥补部分地面通信系统特殊情况下容量不足的缺点。然而,虽然LEO卫星网络有覆盖范围大、吞吐量高、功能性强的特点,但由于卫星位置较高,受时延和功率的限制,地面移动用户较难受益于LEO卫星网络。为解决这一难题,提出在地面通信网络与LEO卫星网络混合组网场景中使用5G标准提出的上下行解耦技术,即地面移动用户上行通过地面基站传输,下行通过卫星传输。利用LEO卫星提供的高频谱、大覆盖服务,可以高效提高系统吞吐量与可靠性,同时满足终端设备的时延和功耗要求。通过建立模型比较解耦架构与非解耦架构下的排队时延和切换失败概率,分析比较两种架构的性能。仿真结果表明,解耦系统在业务高峰时段具有明显的性能优势。With the development of communication technology,satellite communication,especially LEO satellite communication,will become an important part of next generation mobile communication systems.In addition,with the emergence of comprehensive sensing,reliable transmission and intelligent processing for intelligent transportation communication systems,the railway communication network based on LEO satellite network can be considered to effectively solve the problem of communication quality degradation in the intelligent transportation field,especially the communication quality degradation caused by high mobility of high-speed railways,thereby reducing the handover times of some links through the large area coverage of satellites downlink,enhancing the communication link reliability,and making up for the deficiency of some ground communication systems under special scenarios.However,despite the large coverage,high throughput and strong resilience of LEO satellite network,it is hard for ground mobile devices to benefit from the LEO satellite network due to the limitation of delay and power caused by high satellite altitude.To address the dilemma,this paper proposed to use the uplink and downlink decoupling technology proposed by 5G standard,in which the uplink of ground mobile users is transmitted through the ground base station,and the downlink is transmitted through the LEO satellite base station under the hybrid network of ground communication networks and LEO satellite network.The high-frequency and wide-coverage service provided by LEO satellites can be utilized as efficiently as possible to improve the throughput and reliability,while the delay and power consumption requirements of terminal equipment can be guaranteed.A probability model was established to analyze the queueing delay and handover failure probabilities,and compare the handover performance under decoupling and non-decoupling architectures.The simulation results demonstrate the high performance advantages of the decoupling system,especially during peak

关 键 词：低轨卫星网络 轨道交通 上下行解耦 性能分析 

分 类 号：TN92[电子电信—通信与信息系统]