基于Fischer算法的地铁公用通信系统比特功率分配研究  

Study on Bit and Power Allocation for Subway PublicCommunication System Based on Fischer Algorithm

作　　者：程璇 高云波[1] 李茂青[1] 王国荣 马瑞 CHENG Xuan;GAO Yun-bo;LI Mao-qing;WANG Guo-rong;MA Rui(School of Automation and Electrical Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学自动化与电气工程学院,兰州730070

出　　处：《兰州交通大学学报》2021年第6期55-61,共7页Journal of Lanzhou Jiaotong University

基　　金：国家自然科学基金(62161016,61661025,52167013);甘肃省自然科学基金(20JR10RA210);甘肃省科技计划资助(20JR10RA273);光电技术与智能控制教育部重点实验室(兰州交通大学)开放课题(KFKT2019-)。

摘　　要：立足我国地铁网络架构及频分双工模式应用现状,研究地铁公用无线通信系统中正交频分复用固定调制时数据误比特率较高问题,将自适应Fischer算法应用到单用户在其子载波集上的比特功率分配过程.首先,以固定总发送功率、固定总传输速率为约束条件,以实现最小误比特率为目标建立优化模型,该模型更贴合地铁公用通信系统实际场景;其次,基于拉格朗日定理推导了Fischer算法的比特与功率分配的闭式解;最后,复杂度分析表明,Fischer算法实时性更好,更适用于高速传输系统.仿真结果表明,自适应策略可依据信道状况进行比特及功率分配,Fischer算法更为灵敏,且其误比特率性能明显优于固定调制下的等比特功率分配.Based on China's subway network architecture and the application status of frequency division duplex mode,this paper studied the problem of high bit error rate in traditional orthogonal frequency division multiplexing fixed modulation of the subway public wireless communication system.The adaptive Fischer algorithm was applied to the bit and power allocation process of a single user on its sub carrier set.First,taking fixed total transmission power and fixed total transmission rate as constraints and aiming at achieving minimum bit error rate,an optimization model was established,which was more suitable for the actual scene of subway public communication system.Secondly,a closed form solution for the bit and power allocation of Fischer algorithm was derived based on Lagrange's theorem.Finally,the complexity analysis shows that Fischer algorithm has better real time performance,and it is more suitable for high speed transmission systems.Simulation results show that adaptive strategy can allocate bits and power according to the channel conditions,and Fischer algorithm is more sensitive that its bit error rate performance is significantly better than the equal bit and power allocation under fixed modulation.

关 键 词：地铁公用无线通信系统 正交频分复用 比特功率分配 自适应Fischer算法 

分 类 号：TN929.5[电子电信—通信与信息系统]