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Multi-Vehicle Cooperative Positioning Based on Edge-Computed Multidimensional Scaling

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China Communications 2021年第6期18卷 53-63页

作者： Bin Yang Rui Chen Bin li changle li State Key Laboratory of ISN Xidian UniversityXi’an 710071China Shaanxi Key Laboratory of Integrated and Intelligent Navigation Xi’an 710068China

As the basis of location-based services(LBS),positioning is one of the most essential parts in intelligent transportation systems(ITS).Although global positioning system(GPS)has been widely used in vehicle positioning,it can not achieve lane level positioning *** by the mature ranging technologies such as radar and ultra-wideband(UWB),several cooperative positioning(CP)methods have been proposed to enhance the accuracy and robustness of *** this paper,we proposed a twostage CP algorithm that combines multidimensional scaling(MDS)and Procrustes analysis for vehicles with GPS ***,the optimized MDS based on the scaling by majorizing a complicated function(SMACOF)algorithm is first proposed to get the relative coordinates of vehicles which can tackle measurements of different error distributions,then Procrustes analysis is carried out to transform the relative coordinates of vehicles to their absolute coordinates based on GPS *** the computations are performed at the mobile edge computing node(MECN)for the request of ultra-reliable and low latency communications(URLLC).Simulation results validate that the proposed algorithm can greatly improve the positioning accuracy and robustness for vehicles.

关键词： intelligent transportation systems(ITS) Internet of vehicles(IoV) multidimensional scaling(MDS) positioning Procrustes analysis

Evolution of Road Traffic Congestion Control:A Survey from Perspective of Sensing,Communication,and Computation

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China Communications 2021年第12期18卷 151-177页

作者： Wenwei Yue changle li Guoqiang Mao Nan Cheng Di Zhou State Key Laboratory of Integrated Services Networks Xidian UniversityXi’an 710126ShaanxiChina Research Institute of Smart Transportation Xidian UniversityXi’an 710126ShaanxiChina

Road traffic congestion can inevitably de-grade road infrastructure and decrease travel efficiency in urban traffic networks,which can be relieved by employing appropriate congestion ***-ing to different developmental driving forces,in this paper,the evolution of road traffic congestion control is divided into two *** ever-growing num-ber of advanced sensing techniques can be seen as the key driving force of the first stage,called the sens-ing stage,in which congestion control strategies ex-perienced rapid growth owing to the accessibility of traffic *** the second stage,i.e.,the communica-tion stage,communication and computation capabil-ity can be regarded as the identifying symbols for this stage,where the ability of collecting finer-grained in-sight into transportation and mobility reality improves dramatically with advances in vehicular networks,Big Data,and artificial ***,as the pre-requisite for congestion control,in this paper,ex-isting congestion detection techniques are first elab-orated and ***,a comprehensive survey of the recent advances for current congestion control strategies with a focus on traffic signal control,vehi-cle route guidance,and their combined techniques is *** this regard,the evolution of these strate-gies with continuous development of sensing,com-munication,and computation capability are also ***,the paper concludes with several re-search challenges and trends to fully promote the in-tegration of advanced techniques for traffic congestion mitigation in transportation systems.

关键词： road traffic congestion control congestion detection traffic signal control vehicle route guid-ance sensing techniques communication and compu-tation capability

Cluster-Based Content Download and Forwarding Scheme for Highway VANETs

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China Communications 2018年第4期15卷 110-120页

作者： mingsi zhang changle li tao guo yuchuan fu State Key Laboratory of Integrated Services Networks Xidian University Shaanxi 710071 China.

The recent advances in wireless communication technology enable high-speed vehicles to download data from roadside units(RSUs). However, the data download volume of individual vehicle is rather restricted due to high mobility and limited transmission range of vehicles, bringing users poor performance. To address this issue, we exploit the combination of both clustering and carry-and-forward schemes in this paper. Our scheme coordinates the cooperation of multiple infrastructures, cluster formation in the same direction and data forwarding of reverse vehicles to facilitate the target vehicle to download large-size content in dark areas. The process of data dissemination and achievable data download volume are then derived and analyzed theoretically. Finally, we conduct extensive simulations to verify the performance of the proposed scheme. Results show significant benefits of the proposed scheme in terms of increasing data download volume and throughput.

关键词： clustering carry-and-forward^data dissemination data download volume

IoV and Blockchain-Enabled Driving Guidance Strategy in Complex Traffic Environment

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China Communications 2023年第12期20卷 230-243页

作者： Yuchuan Fu changle li Tom H.Luan Yao Zhang State Key Laboratory of Integrated Services Networks Xidian UniversityXi’an 710071China Research Institute of Smart Transportation Xidian UniversityXi’an 710071China Northwestern Polytechnical University Xi’an 710072China

Diversified traffic participants and complex traffic environment(e.g.,roadblocks or road damage exist)challenge the decision-making accuracy of a single connected and autonomous vehicle(CAV)due to its limited sensing and computing *** Internet of Vehicles(IoV)to share driving rules between CAVs can break limitations of a single CAV,but at the same time may cause privacy and safety *** tackle this problem,this paper proposes to combine IoV and blockchain technologies to form an efficient and accurate autonomous guidance ***,we first use reinforcement learning for driving decision learning,and give the corresponding driving rule extraction ***,an architecture combining IoV and blockchain is designed to ensure secure driving rule ***,the shared rules will form an effective autonomous driving guidance strategy through driving rules selection and action *** simulation proves that the proposed strategy performs well in complex traffic environment,mainly in terms of accuracy,safety,and robustness.

关键词： autonomous driving guidance blockchain communication range Internet of Vehicles reinforcement learning

Source Recovery in Underdetermined Blind Source Separation Based on Artificial Neural Network

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China Communications 2018年第1期15卷 140-154页

作者： Weihong Fu Bin Nong Xinbiao Zhou Jun liu changle li School of Telecommunication engineering Xidian University Xi'an Shaanxi 710071 China Collaborative innovation center of information sensing and understanding Xi'an Shaanxi 710071 China National Laboratory of Radar Signal Processing Xidian University Xi'an Shaanxi 710071 China

We propose a novel source recovery algorithm for underdetermined blind source separation, which can result in better accuracy and lower computational cost. On the basis of the model of underdetermined blind source separation, the artificial neural network with single-layer perceptron is introduced into the proposed algorithm. Source signals are regarded as the weight vector of single-layer perceptron, and approximate ι~0-norm is taken into account for output error decision rule of the perceptron, which leads to the sparse recovery. Then the procedure of source recovery is adjusting the weight vector of the perceptron. What's more, the optimal learning factor is calculated and a descent sequence of smoothed parameter is used during iteration, which improves the performance and significantly decreases computational complexity of the proposed algorithm. The simulation results reveal that the algorithm proposed can recover the source signal with high precision, while it requires lower computational cost.

关键词： underdetermined blind source separation ι~0-norm artificial neural network sparse reconstruction

Critical Nodes Identification: A Non-Cooperative Method for Unknown Topology Information in Ad Hoc Networks

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China Communications 2023年第7期20卷 217-232页

作者： Wenwei Yue Peiang Zuo Wengang li Yao Zhang Yunfeng Zhang changle li Jun Huang State Key Laboratory of Integrated Services Networks Xidian UniversityXi’anShaanxi 710071China Research Institute of Smart Transportation Xidian UniversityXi’anShaanxi 710071China National University of Defense Technology HefeiAnhui 410073China

The foundation of ad hoc networks lies in the guarantee of continuous ***,critical nodes,whose failure can easily destroy network connectivity,will influence the ad hoc network connectivity *** protect the network efficiently,critical nodes should be identified accurately and *** existing critical node identification methods for unknown topology that identify critical nodes according to historical information,this paper develops a critical node identification method to relax the prior topology information condition about critical ***,we first deduce a theorem about the minimum communication range for a node through the number of nodes and deployment ranges,and prove the universality of the theorem in a realistic two-dimensional *** that,we analyze the relationship between communication range and degree value for each node and prove that the greater number of nodes within the communication range of a node,the greater degree value of nodes with high ***,we develop a novel strategy to improve the accuracy of critical node identification without topology ***,simulation results indicate the proposed strategy can achieve high accuracy and low redundancy while ensuring low time consumption in the scenarios with unknown topology information in ad hoc networks.

关键词： Ad hoc networks node location informa-tion ID generation strategy communication range critical nodes

Integrated Sensing,Computing and Communications Technologies in IoV and V2X

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China Communications 2023年第3期20卷 I0002-I0004页

作者： Shanzhi Chen FRichard Yu Weisong Shi changle li China Information and Communication Technology Group Co. Ltd.(CICT) State Key Laboratory of Wireless Mobile Communications SMIC IEEE VTS Mobile World newsletter IEEE Canadian Academy of Engineering(CAE) Engineering Institute of Canada(EIC) IET Department of Computer and Information Sciences at the University of Delaware(UD) State Key Laboratory of Integrated Services Networks of Xidian University

With the development of new generation of information and communication technology,the Internet of Vehicles(IoV)/Vehicle-to-Everything(V2X),which realizes the connection between vehicle and X(i.e.,vehicles,pedestrians,infrastructures,clouds,etc.),is playing an increasingly important role in improving traffic operation efficiency and driving safety as well as enhancing the intelligence level of social traffic services.

关键词： driving traffic operation

BROADCAST SCHEDUliNG WITH MIMO liNKS IN MULTI-HOP AD HOC NETWORKS

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Journal of Electronics(China) 2007年第4期24卷 477-483页

作者： Zhang Guanghui li Jiandong Zhao Min li changle State Key Lab. of ISN Information Science Inst. Broadband Wireless Communications Lab. Xidian University Xi＇an 710071 China

As the current medium access control protocols with Multiple Input Multiple Output （MIMO） links only bear point to point service, broadcast scheduling algorithm in ad hoc networks with MIMO links is proposed. The key to the proposed broadcast scheduling algorithm is the time slot scheduling algorithm which guarantees collisi~）n-free transmissions for every node and the mini- mum frame length. The proposed algorithm increases the simultaneous transmissions of MIMO links efficiently. Due to the interference null capacity of MIMO links, the interference node set of each node can decrease from two-hop neighbors to one-hop neighbors possibly. Simulation results show that our algorithm can greatly improve network capacity and decrease average packet delay.

关键词： Multiple Input Multiple Output (MIMO) Time Division Multiple Access (TDMA) Broadcast Multihop ad hoc network

Cooperative effects of hydrogen sulfide and nitric oxide on delaying softening and decay of strawberry

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International Journal of Agricultural and Biological Engineering 2014年第6期7卷 114-122页

作者： Zhang Chang Shi Jingying Zhu liqin li changle Wang Qingguo College of Food Science and Engineering Shandong Agricultural UniversityTaian 271018China College of Food Science and Engineering Jiangxi Agricultural UniversityNanchang 330045China

Hydrogen sulfide(H2S)and nitric oxide(NO)as two signal molecules play prominent roles in plant response to biotic *** combination effects of these two molecules on ripening and decay of postharvest strawberry were *** were first dipped in distilled water,0.8 mmol/L NaHS solution,5μmmol/L sodium nitroprusside(SNP)solution,and combinative solutions of 0.8 mmol/L NaHS and 5μmmol/L SNP for 10 min,respectively,and then stored at 20°*** showed that the effects of the co-treatment of 0.8 mmol/L NaHS solution and 5μmmol/L SNP solution were superior to that of other *** former could suppress the percentage of fruit decay,inhibit respiration rate,maintain the original crust color,and slow down the decrease of firmness and the change of relative conductivity,which preserved the fruit *** investigation showed that co-treatment of hydrogen sulfide and nitric oxide maintained higher activities of chitinase(CHI)and beta-1,3-glucanase(GNS),and lowered activities of pectin methylesterase(PME),polygalacturonase(PG)and endo-β-1,4-glucanase(EGase).The study indicated that the synergistic function of H2S and NO could effectively prolong the shelf life and reduce the decay rate of harvested strawberry.

关键词： hydrogen sulfide nitric oxide strawberry enzyme activities shelf life