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Environmental Information-Aided Electromagnetic Propagation Testbed for Maritime Communication

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China Communications 2023年第3期20卷 302-315页

作者： Ting Zhou Yuzhen Wang Bilian Xu Tianheng Xu Xiaoming Tao Honglin Hu Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of ScienceBeijing 100049China School of Microelectronics Shanghai UniversityShanghai 200444China Department of Electronic Engineering Tsinghua UniversityBeijing 100084China

Maritime channel modeling can be affected by some key time-varying environmental *** ducting effect is one of the thorniest factors since it causes anomalous propagation enhancement and severe co-channel ***,the atmospheric attenuation is much more severe in the ocean environment,resulting in shorter coverage distance and more link *** this paper,we propose an environmental information-aided electromagnetic propagation *** is based on complex refractivity estimation and improved parabolic equation propagation model,taking into account both ducting effect and atmospheric attenuation.A large-scale temporal and spatial propagation measurement was conducted with meteorological *** consider practical path loss and ducting conditions to verify the testbed feasibility in these long-distance radio *** simulation results are in good agreement with the measured data,which further reveal the basic temporal and spatial distribution of ducting effect at 3.5 GHz band.

关键词： broadband maritime communication maritime channel ducting effect electromagnetic propagation testbed propagation measurement atmospheric attenuation path loss

An Optimization Forwarding Range Routing Protocol for VANET in City Environments

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Chinese Journal of Electronics 2014年第1期23卷 191-193页

作者： LI Xiaoqing LI Hui YANG Kai LIU Qiao The State Key Laboratory of Integrated Service Networks Xidian University Department of Electronics Technology Engineering University of CAPF

In city environment, the vehicle communication is affected by the around obstacles due to the especial condition of wireless channels. However, most of prior works adopt the fixed radio range value of vehicles to transmit packets. In this paper, we design an optimization forwarding range routing protocol for VANET in urban *** has an optimized and adjustable forwarding range, which changes with different environments based on the path loss and the city model. And the proposed geo-routing protocol has a novel idea in computing the connectivity of roads and the adjustable strategy in a sparse network. Simulation results indicate that the OFRR enjoys desirable performance in the urban area.

关键词： Vehicular ad hoc network(VANET) Optimal forwarding range path loss Routing protocol

Energy Efficient Power Allocation Scheme for Distributed Antenna Systems with Target BER Constraint

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China Communications 2016年第11期13卷 234-243页

作者： Xiangbin Yu Ying Wang Qiuming Zhu Tao Dong Junya Chu Jiangsu Key Laboratory of Internet of Things and Control Technologies College of Electronic and Information EngineeringNanjing University of Aeronautics and Astronautics National Mobile Communications Research Laboratory Southeast University Shenzhen Research Institute Nanjing University

The energy efficiency(EE) of distributed antenna system with quality of service(Qo S) requirement is investigated over composite Rayleigh fading channel,where the shadow fading,path loss and Rayleigh fading are all considered. Our aim is to maximize the EE which is defined as the ratio of the transmission rate to the total consumed power subject to the maximum transmit power of each remote antenna constraint and Qo S(target BER) requirement. According to the definition of EE and using the upper bound of average EE,the optimized objective function is provided. Based on this,utilizing Karush-KuhnTucker conditions and numerical calculation,a suboptimal energy efficient power allocation(PA) scheme is developed,and the closedform expression of PA coefficients is derived. The scheme may obtain the EE performance close to the existing optimal scheme. Moreover,it has relatively lower complexity than the existing scheme because only the statistic channel information and less iteration are required. Simulation results show the presented scheme is valid and can meet the target BER requirement,and the EE can be increased as target BER requirement decreases.

关键词： distributed antenna system energy efficiency power allocation target bit error rate(ber) shadow fading path loss

Capacity Analysis on Distributed Antenna System with Imperfect CSI over Rayleigh Fading Channel

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Transactions of Nanjing University of Aeronautics and Astronautics 2016年第6期33卷 -页

作者： Wu Binbin Yu Xiangbin Wang Ying Li Yang Qiu Sainan Jiangsu Key Laboratory of Internet of Things and Control Technologies College of Electronic and Information EngineeringNanjing University of Aeronautics and Astronautics

Considering that perfect channel state information(CSI)is hard to obtain in practice,the capacity of downlink distributed antennas system(DAS)with imperfect CSI is analyzed over Rayleigh fading *** on the performance analysis,using the probability density function and numerical calculation,an accurate closedform expression of ergodic capacity of downlink DAS under imperfect CSI is *** includes the one under perfect CSI as a special *** theoretical expression can provide good performance evaluation for downlink DAS for both perfect and imperfect CSI due to its *** results indicate that the theoretical analysis agrees well with the corresponding simulation,and the capacity can be increased effectively by decreasing the estimation error and/or path loss.

关键词： distributed antenna system capacity analysis imperfect CSI downlink path loss

Analysis and Modeling of Propagation in Tunnel at 3.7 and 28 GHz

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Computers, Materials & Continua 2022年第5期71卷 3127-3143页

作者： Md Abdus Samad Dong-You Choi Department of Information and Communication Engineering Chosun UniversityGwangju61452Korea Department of Electronics and Telecommunication Engineering International Islamic University ChittagongChittagong4318Bangladesh

In present-day society,train tunnels are extensively used as a means of ***,to ensure safety,streamlined train operations,and uninterrupted internet access inside train tunnels,reliable wave propagation modeling is *** have experimented and measured wave propagation models in a 1674 m long straight train tunnel in South *** measured path loss and the received signal strength were modeled with the Close-In(CI),Floating intercept(FI),CI model with a frequency-weighted path loss exponent(CIF),and alpha-beta-gamma(ABG)models,where the model parameters were determined using minimum mean square error(MMSE)*** measured and the CI,FI,CIF,and ABG modelderived path loss was plotted in graphs,and the model closest to the measured path loss was identified through *** on the measured results,it was observed that every model had a comparatively lower(npath loss exponent(PLE)inside the *** also determined the path loss component’s possible deviation(shadow factor)through a Gaussian distribution considering zero mean and standard deviation calculations of random error *** FI model outperformed all the examined models as it yielded a path loss closer to the measured datasets,as well as a minimum standard deviation of the shadow factor.

关键词： path loss shadow factor telecommunications train tunnel wave propagation wireless networks

Indoor channel characteristics based on wideband MIMO measurements at 5.25 GHz

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The Journal of China Universities of Posts and Telecommunications 2008年第4期15卷 46-50页

作者： GAO Xin-ying ZHANG Jian-hua ZHANG Ping Key Laboratory of Universal Wireless Communications Ministry of Education Wireless Technology Innovation Institute Beijing University of Posts and Telecommunications Beijing 100876 China

Extensive indoor channel measurements were conducted in Beijing with wideband multiple-input multiple-output （MIMO） sounder at 5.25 GHz. Both line-of-sight （LOS） and non-line-of-sight （NLOS） propagation were measured in the indoor office and hotspot scenarios. On the basis of measured data, statistical channel characteristics are presented in this article, including the empirical path loss （PL） models, three excess delay parameters, circular azimuth spread （CAS）, and circular elevation spread （CES）. Comparative analysis of different propagation mechanisms in two scenarios is conducted. These values are significant for indoor coverage and technical research of MIMO and orthogonal frequency division multiplexing （OFDM） for the international mobile telecommunications-advanced （IMT-Advanced） system.

关键词： channel measurement wideband MIMO path loss excess delay circular azimuth spread circular elevation spread IMT-Advanced

A General Channel Model for Visible Light Communications in Underground Mines

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China Communications 2018年第9期15卷 95-105页

作者： Jia Wang Ahmed Al-Kinani Wensheng Zhang Cheng-Xiang Wang Li Zhou Shandong Provincial Key Lab of Wireless Communication Technologies Shandong University Technical Affairs Department Iraqi Ministry of Communications State Key Laboratory of Mobile Communications Southeast University

In underground mines, visible light communication(VLC) system is a promising method to realize effective communication,which supports communication and illumination at the same time. Therefore, adequate research of underlying physical propagation phenomenon should be carried out to realize VLC system in underground mines. To design VLC system and evaluate its performance, accurate and efficient channel models, including large-scale fading and scattering characteristics, are needed to be established. However,the characteristics of the underlying VLC channels about fading and scattering have not been sufficiently investigated yet. In this paper, a path loss channel model, based on the recursive model, is proposed precisely. Its path loss exponent is determined by three different trajectories, which is studied in the mining roadway and working face environment. Besides, the shadowing effect for VLC has been modelled by a Bimodal Gaussian distribution in underground mines. Considering the number of transmitters in line-of-sight(Lo S) as well as non-line-of-sight(NLo S) scenarios,our simulation illustrates the fact that, as the curve fitting technique is employed, the path loss displays a linear behavior in *** path loss expression is derived, it is related to the distance. Finally, root mean square(RMS) delay spread and Mie scattering in underground mines are analyzed.

关键词： underground mines visible light communications channel modeling path loss shadowing delay spread.

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

Attack Simulation Model and Channel Statistics in Underwater Acoustic Sensor Networks

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Tsinghua Science and Technology 2011年第6期16卷 611-621页

作者： Nan Jing Weihong Bi Qing Yue College of Information Science and Engineering Yanshan University Qinhuangdao 066004 China Qinhuangdao City Public Security Bureaus Qinhuangdao 066000 China

In recent years, underwater acoustic wireless sensor networks have been used in many areas. There have been many field trials of acoustic propagation models and statistics for shallow water conditions. However, field trials are limited environmentally and, hence, not widely accepted. Simulations of the impulse response of a shallow underwater acoustic channel allows less expensive system tests that are reproducable. This paper presents a shallow water acoustic channel model based on the actual acoustic propagation characteristics with path attenuation, ambient noise, multiple paths, and Doppler effects. The second-order statistical characteristics of the simulation model are verified with the autocorrelations and crosscorrelations of the quadrature components and the complex envelopes of channel impulse responses. The channel model is implemented in Matlab with the results showing that the absorption coefficient and path losses are both dependent on the frequencies and propagation distances and that the path gain can be improved with Light of Sight （LOS） and short range acoustic propagation. Analysis of the channel impulse response and the frequency response that the zero-order Bessel function of first kind can be used to describe the correlation functions for the impulse response. The shallow underwater acoustic channel is time-varying and can not be modeled as a wide-sense stationary-uncorrelated scattering channel.

关键词： simulation model absorption coefficient path loss Doppler statistical characteristics