摘要
研究目的:针对CBTC系统车-地通信过程产生的高时延、系统容量不足等情况,进而引发系统瞬时通信中断的问题,对其影响因素进行分析,提出一种CBTC系统车-地通信性能的优化方案,并通过建模仿真验证其有效性。根据CBTC系统的时变信道不完全信道状态信息特征,用接收端信噪比低于拟设阈值的概率,即中断概率作为车-地通信性能的评价指标,建立数学模型表述其与轨旁通信节点位置、信道小尺度衰落和列车位置等决策变量的关系,利用改进的Powell方向加速算法对目标函数的解进行迭代优化,得到全局最优解。研究结论:(1)利用降低列车速度、降低车-地信息传输速率、改善通信信道环境等方法,可降低车-地通信中断概率,但寻求轨旁通信节点的最优布置方式是改善CBTC系统车-地通信性能的最佳方案,且成本最低;(2)与随机搜索方法相比,通过改进的Powell方向加速算法求解模型中的无约束优化问题,展现出高效性,收敛速度比随机搜索快80%以上;(3)通过优化中断概率,可为提升CBTC系统车-地通信性能提供理论指导,为城轨施工轨旁通信节点设置问题提供解决方案。
Research purposes:Aiming at the problems of instantaneous communication interruption caused by high time delay and insufficient system capacity influenced in the process of train-to-ground(T2G)communication in CBTC system,this paper analyzes affecting factors,proposes an optimization scheme for T2G communication performance in CBTC system,and verifies its effectiveness through modeling and simulation.According to the characteristics of timevarying channel incomplete channel state information in CBTC system,the probability of receiving signal-to-noise ratio lower than proposed threshold,outage probability,is used as evaluation index of T2G communication performance,and a mathematical model is established to express its relationship with decision variables such as the location of trackside access points,small-scale channel decay and train position.The modified Powell direction acceleration algorithm is used to perform iterative optimization on solution of the objective function,and global optimal solution is obtained.Research conclusions:(1)Reducing train speed,reducing T2G information transmission rate and improving communication channel environment can reduce T2G communication outage probability,but seeking the optimal arrangement of trackside access points is the best scheme to improve T2G communication performance in CBTC system,and cost is the lowest.(2)Compared with random search,the modified Powell direction acceleration algorithm used to solve the unconstrained optimization problem in the model shows high efficiency,and the convergence rate is more than 80%faster than random search.(3)The research results can provide theoretical guidance for improving T2G communication performance of CBTC system by optimizing outage probability,and provide a solution for the problem of trackside access point setting in urban rail construction.
作者
杨骞
苏宏升
杨建刚
刘大为
董煜
YANG Qian;SU Hongsheng;YANG Jiangang;LIU Dawei;DONG Yu(Lanzhou Jiaotong University,Lanzhou,Gansu 730070,China;Lanzhou Institute of Technology,Lanzhou,Gansu 730050,China;CRSC Research&Design Institute Group Co.Ltd,Beijing 100070,China)
出处
《铁道工程学报》
2025年第1期95-100,共6页
Journal of Railway Engineering Society
基金
甘肃省高校青年博士支持项目(2023QB-049)
甘肃省高校教师创新基金项目(2025B-239)。
作者简介
杨骞,1987年出生,男,讲师;通讯作者:苏宏升,1969年出生,男,教授。
