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The Real-Time Simulation of Doppler Spread in Wireless Mobile Environment by RF Circuits

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Chinese Journal of Electronics 2015年第4期24卷 837-843页

作者： LI Zhen ZHU Xiang JI Wenli zheng guoxin Key Laboratory of Specialty Fiber Optics and Optical Access Networks Shanghai University Technical Center of Shanghai Shentong Metro Group Co .Ltd

The time-varying characteristic of wireless channel under the high-speed mobile environments in tunnels causes the Doppler spread to the transmitted signals,which affects the performance of wireless communication systems. The real-time Doppler effect simulation methodology directly based on Radio frequency(RF) circuits is proposed to simulate different Doppler spread effects in real environments. Mixers and a Digital-to-analog(DA)converter circuit are utilized to spread the spectrum of RF signals. A PC platform with the interface written in C#is configured to control the spectrum spread *** radio channel emulator with the proposed methodology can replace the expensive fading simulating instruments with only 25.1ns system delay. Such an emulator has been applied to test the Multi-carrier wireless information local loop(McW i LL) wireless vehicle communication system in the laboratory to meet the requirement of metro Communication based train control(CBTC) system.

关键词： Doppler spread Channel simulation Circuits Tunnel Metro system

A Survey on Channel Measurements and Models for Underground MIMO Communication Systems

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China Communications 2023年第8期20卷 103-119页

作者： Asad Saleem Yejun He guoxin zheng Zhining Chen State Key Laboratory of Radio Frequency Heterogeneous Integration Guangdong Engineering Research Center of Base Station Antennas and PropagationShenzhen Key Laboratory of Antennas and PropagationCollege of Electronics and Information EngineeringShenzhen UniversityShenzhen 518060China Key Laboratory of Specialty Fiber Optics and Optical Access Networks Shanghai UniversityShanghai 200444China Department of Electrical and Computer Engineering National University of SingaporeSingapore

The high reliability of the communication system is critical in metro and mining applications for personal safety,channel optimization,and improving operational *** paper surveys the progress of wireless communication systems in underground environments such as tunnels and mines from 1920 to 2022,including the evolution of primitive technology,advancements in channel modelling,and realization of various wireless propagation *** addition,the existing and advanced channel modeling strategies,which include the evolution of different technologies and their applications;mathematical,analytical,and experimental techniques for radio propagation;and significance of the radiation characteristics,antenna placement,and physical environment of multiple-input multiple-output(MIMO)communication systems,are *** given study introduces leaky coaxial cable(LCX)and distributed antenna system(DAS)designs for improving narrowband and wideband channel *** paper concludes by figuring out open research areas for the future technologies.

关键词： leaky coaxial cable(LCX) long-term evolution for metro(LTE-M) multiple-input multipleoutput(MIMO)systems propagation modeling

Fractional Fourier Transform Based M-ary Chirp Modulation

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Journal of Shanghai Jiaotong university(Science) 2020年第6期25卷 795-801页

作者： SHA Jiajun zheng guoxin YANG Lin Key Laboratory of Specialty Fiber Optics and Optical Access Networks Joint Internat ional Research Laboratory of Specialty Fiber Optics and Advanced CommunicationShanghai Institute of Advanced Communication and Data ScienceShanghai UniversityShanghai 200072China School of Electronic and Information Shanghai Dianji UniversityShanghai 201306China

In this paper,a novel M-ary chirp modulation scheme is proposed on the basis of the energy concen-tration property of chirp signals in fractional *** the proposed scheme,chirp signals with diferent phases are multiplexed in the same time frequency bandwidth through reverse chirp rate to increase information *** addition,fractional filters based on fractional Fourier transform(FRFT)are designed to separate chirp signals of diferent chirp-rates in the ***,the theoretical performance of fractional filters and the error probability of M-ary chirp system are *** theoretical analysis and simulation prove that the proposed scheme outperforms M-ary quadrature amplitude modulation(QAM)system in the anti-noise performance.

关键词： chirp modulation fractional Fourier transform(FRFT)filter M-ary chirp

Measurements and analysis at 400MHz and 2600MHz in corridor radio channel

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High Technology Letters 2016年第4期22卷 412-418页

作者：尹晓宇 zheng guoxin Ding Qingfeng Wang Tao Qiao Yantao Key Laboratory of Specialty Fiber Optics and Optical Access Networks Shanghai UniversityShanghai 200072P.R.China School of Electrical and Electronic Engineering East China Jiaotong UniversityNanchang 330013P.R.China Department of Computer and Information Science University of Michigan Dearborn 48128USA

A propagation measurement campaign was performed at the 10 th floor corridor of Xingjian Building,Shanghai University,*** channel was sounded by pseudo noise( PN) sequence at carrier frequencies of 400-and 2600-MHz *** order to obtain large scale and small scale propagation characteristics in the corridor,the receiver was moved along the corridor every 1.02 meter to record the impulse *** than 280,000 impulse responses were recorded in the *** work first describes the principle of the measurement,and then how the recorded raw data are *** results show that path loss exponent is related to *** relationship between the root-mean squared( RMS) delay spread and the T-R separation distance is *** RMS delay spread and the mean excess delay spread against path loss are also given,which explain why the 2600 MHz RMS delay spread is larger than that of 400 MHz.

关键词： path loss root-mean squared(RMS) delay spread corridor channel measurement

地震灾害下配电网的脆弱性分析及弹性提升措施

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电网技术 2021年第9期45卷 3674-3680页

作者：雷霞郑国鑫胡益西华大学电气与电子信息学院四川省成都市610039

地震灾害对配电网的影响极大,会导致大范围停电,而高弹性配电网具有抵御地震灾害和灾后紧急供电的能力。针对地震灾害下配电网的弹性提升问题,首先对配电网区域进行网格化划分,结合地震动衰减方程,求出各个网格的地震动大小;再根据威布... 详细信息

地震灾害对配电网的影响极大,会导致大范围停电,而高弹性配电网具有抵御地震灾害和灾后紧急供电的能力。针对地震灾害下配电网的弹性提升问题,首先对配电网区域进行网格化划分,结合地震动衰减方程,求出各个网格的地震动大小;再根据威布尔分布下配网线路的可靠性模型以及地震灾害下配网线路的脆弱性模型,建立配网线路的综合故障率模型,计算出多个地震场景下系统的信息熵,以找出配电网中极易受损的线路;其次针对线路加固和分布式电源最优配置的弹性提升措施进行建模,将其转化为两阶段整数线性规划问题,第1阶段以总投资费用最小为目标函数,第2阶段的目标是根据系统功能曲线在灾害中的变化建立配电网的弹性评估指标并使其最大化;最后以IEEE33节点测试系统为例,进行地震灾害下配电网的弹性分析,比对配电网采取提升措施前后的弹性指标,验证了所提方法的可行性。

关键词：地震弹性配电网网格化故障率模型弹性提升措施

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地震灾害模拟及配电网的风险评估

电工技术学报 2020年第24期35卷 5218-5226页

作者：郑国鑫雷霞王湘罗小春西华大学电气与电子信息学院成都610039 国网四川省电力公司阿坝供电公司阿坝州602300

地震对电力系统的损害极为严重,而配电网的抵御能力相对输电网来说更为脆弱,因此有必要对遭受地震灾害的配电网进行风险评估。该文首先根据地震动参数衰减方程估算出配电网区域的地震动强度,结合配电网设备的脆弱性模型计算出受损设备... 详细信息

地震对电力系统的损害极为严重,而配电网的抵御能力相对输电网来说更为脆弱,因此有必要对遭受地震灾害的配电网进行风险评估。该文首先根据地震动参数衰减方程估算出配电网区域的地震动强度,结合配电网设备的脆弱性模型计算出受损设备的比例;然后通过蒙特卡洛模拟随机地震,寻找地震中概率最大的配电网故障重数以进行故障场景模拟;综合考虑配电网的运行方式及拓扑结构,以复杂网络理论的网络中心性评估配电网网架的受损性,进行随机地震后配电网的风险评估,以辨识出配电网的薄弱点供灾前预防;最后以四川靠近龙门山断裂带的某10kV配电网为例,进行地震灾害下配电网的风险评估,验证了该文所提方法的可行性。

关键词：地震风险分析脆弱性模型蒙特卡罗模拟网络中心性

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隧道环境下车地LTE-M系统时变信道仿真

上海大学学报（自然科学版） 2019年第1期25卷 45-55页

作者：吴慧泽郑国莘上海大学特种光纤与光接入网省部共建重点实验室上海200444

为建设物理信道检测平台以验证TD-LTE (time division long term evolution)技术用于轨道交通基于通信的列车控制(communication based train control, CBTC),从而实现无线通信的可靠性.对车地通信信道建模,并采用时频分析方法研究了在... 详细信息

为建设物理信道检测平台以验证TD-LTE (time division long term evolution)技术用于轨道交通基于通信的列车控制(communication based train control, CBTC),从而实现无线通信的可靠性.对车地通信信道建模,并采用时频分析方法研究了在隧道环境下的车地无线时变信道,特别是列车经过轨旁基站时激烈变化的多普勒效应,提出了基于乘性扩展因子实现信号多普勒扩展的方法,建立了适用于射频电路物理实现的信道仿真模型,并利用射线跟踪法仿真验证了该方法的正确性.

关键词： TD-LTE 隧道环境时变信道多普勒扩展

基于LS-SVM预测的隧道多径环境OFDM系统信道估计算法

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高技术通讯 2013年第9期23卷 888-893页

作者：丁青锋郑国莘杨柳上海大学特种光纤与光接入网重点实验室上海200072 华东交通大学电气与电子工程学院南昌330013

针对隧道环境下多径传播的特点,提出了一种用于正交频分复用(OFDM)系统的基于最小二乘支持向量机(LS-SVM)预测的新型信道估计算法,该算法利用子空间思想将信道特性中的噪声分量分离开来并通过低通滤波器滤除。仿真结果表明该算法估计性... 详细信息

针对隧道环境下多径传播的特点,提出了一种用于正交频分复用(OFDM)系统的基于最小二乘支持向量机(LS-SVM)预测的新型信道估计算法,该算法利用子空间思想将信道特性中的噪声分量分离开来并通过低通滤波器滤除。仿真结果表明该算法估计性能优于传统线性最小均方误差(LMMSE)估计算法:一方面在利用较少导频信号的情况下通过LS-SVM预测获得整个信道的频率特性,提高了系统传输效率;另一方面通过滤除噪声改善了因信道估计值中噪声分量带来的误码率(BER)。

关键词：信道估计最小二乘支持向量机(LS SVM) 低通滤波器线性最小均方误差(LMMSE) 低秩

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轨道交通LTE-M通信系统可靠性分析

上海大学学报（自然科学版） 2019年第6期25卷 859-869页

作者：解钧捷郑国莘上海大学特种光纤与光接入网省部共建重点实验室

结合我国大规模轨道交通建设中基于城市轨道交通的长期演进(long term evolutionmetro,LTE-M)无线通信系统应用于基于通信的列车控制(communication based train control,CBTC)时系统整体构架的问题,从可靠性理论入手,针对CBTC采用1.8 ... 详细信息

结合我国大规模轨道交通建设中基于城市轨道交通的长期演进(long term evolutionmetro,LTE-M)无线通信系统应用于基于通信的列车控制(communication based train control,CBTC)时系统整体构架的问题,从可靠性理论入手,针对CBTC采用1.8 GHz的LTEM专网传输的通信系统,建立了不同系统构架下的可靠性模型并推导了相关公式.借鉴磁浮列车38 GHz专频专网CBTC系统的高可靠性的系统构架,在现有的LTE-M布置方案基础上提出了一种双网冗余及双交叉连接的系统构架,使列车通信系统具有更高的可靠性,为现有LTE-M的大量部署提供了可靠性更高的系统构架建议.

关键词：通信系统轨道交通长期演进可靠性冗余结构