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Packet Transport for Maritime communications:A Streaming Coded UDP Approach

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China communications 2022年第9期19卷 10-25页

作者： Ye Li Jianhao Yu Liang Chen Yingdong Hu Xiaomin Chen Jue Wang School of Information Science and Technology Nantong UniversityNantong 226019JiangsuChina Nantong Research Institute for Advanced Communication Technologies(NRIACT) Nantong 226019JiangsuChina

The maritime communication network(MCN)plays an important role in the 6th generation(6G)system development.In MCNs,packet transport over long-distance lossy links will be ubiquitous.Transmission control protocol(TCP),the dominant transport protocol in the past decades,have had performance issues in such links.In this paper,we propose a novel transport approach which uses user datagram protocol(UDP)along with a simple yet effective bandwidth estimator for congestion control,and with a proactive packet-level forward erasure correction(FEC)code called streaming code to provide low-delay loss recovery without data retransmissions at all.We show that the approach can effectively address two issues of the state-of-the-art TCP variants in the long-distance lossy links,namely 1)the low bandwidth utilization caused by the slow increase of the congestion window(CWND)due to long roundtrip time(RTT)and the frequent CWND drop due to random and congestion losses,and 2)the high endto-end in-order delivery delay when re-transmissions are incurred to recover lost packets.In addition,we show that the scheme’s goodput has good smoothness and short-term intra-protocol fairness properties,which are beneficial for multimedia streaming and interactive applications that are prominent parts of today’s wireless traffic.

关键词： maritime communication network forward-erasure correction congestion control

A Novel Kind of Wideband Low-Profile Dielectric Resonator Antenna Suitable for Beam-scanning Applications

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China communications 2022年第4期19卷 98-107页

作者： Wenjian Sun Yang Yu Yingdong Hu Wenwen Yang Jianxin Chen School of Information Science and Technology Nantong UniversitySeyuan RoadNantong 226019China Nantong Research Institute for Advanced Communication Technologies Chongchuan DistrictNantong 226019China

In this paper, a low-profile wideband dielectric resonator antenna(DRA) with a very compact planar size is investigated. The antenna consists of a high permittivity dielectric sheet on the top, a low permittivity substrate in the middle, and a probe feeding structure at the bottom. By digging an annular slot in the designated area of the square dielectric sheet, the resonant frequency of fundamental TE111 mode can be effectively increased to be close to the high-order TE131 mode. The two modes can be finally merged together, yielding a wide impedance bandwidth of16.6%. Most importantly, the combination of the two modes is done on the premise of a fixed antenna planar size, which can be very compact and suitable for beam-scanning applications. A probe feeding structure is used to excite the DRA, making the antenna simple and practical to be integrated with other RF circuits. For verification, antenna prototypes with singlefeed linear polarization and differential-feed dual polarization were fabricated and measured. Reasonable agreement between the measured and simulated results is observed.

关键词： dielectric resonator antenna compact wideband beam-scanning dual-polarization

Novel spectrum sensing and access in cognitive radio networks

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Science China(Information Sciences) 2018年第8期61卷 228-230页

作者： Shibing ZHANG Yingdong HU Li ZHANG Zhihua BAO School of Electronics and Information Nantong University Nantong Research Institute for Advanced Communication Technologies

Dear editor,The throughput,delay and collision probability between the primary users(PUs)and secondary users(SUs)have been considered as the main performance measures in cognitive radio(CR)networks[1].The longer the s... 详细信息

关键词： net Novel spectrum sensing and access in cognitive radio networks CR

Quantitative Survivability Analysis Using Probability Model Checking: A Study of Cluster-Based Vehicle Networks with Dual Cluster Heads

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China communications 2020年第2期17卷 206-219页

作者： Li Jin Guoan Zhang Jue Wang Hao Zhu Wei Duan School of Information Science and Technology Nantong UniversityNantong 226019China Nantong Research Institute for Advanced Communication Technologies Nantong 226019China

As an important part of future 5G wireless networks,a vehicular network demands safety,reliability and connectivity.In this context,networking survivability is usually considered an important metric to evaluate network performance.In this paper,we propose a survivability model for vehicle communication networking based on dual cluster heads,wherein a backup cluster head(CH)will be activated if the primary CH fails,thereby effectively enhancing the network lifetime.Additionally,we introduce a software rejuvenation strategy for the prime CH to further improve the survivability of the entire network.Using the Probabilistic Symbolic Model Checker(PRISM),we verify and discuss the proposed survivability model via numerical simulations.The results show that network survivability can be effectively improved by introducing an additional CH and further enhanced by adopting the software rejuvenation technique.

关键词： cluster head 5G software recovery survivability vehicle networks

Configurable Virtual MIMO via UAV Swarm:Channel Modeling and Spatial Correlation Analysis

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China communications 2022年第9期19卷 133-145页

作者： Jiachen Qian Jue Wang Shi Jin National Mobile communications research Laboratory Southeast UniversityNanjing 210096China School of Information Science and Technology Nantong UniversityNantong 226109China Nantong Research Institute for Advanced Communication Technologies Nantong 226109China

Air-to-ground wireless channel modeling for unmanned aerial vehicle(UAV)communications has been widely studied.However,channel modeling for UAV swarm-enabled cooperative communication still needs investigation,where the impact of UAV positions on the spatial channel characteristics is of particular importance.In this paper,we consider a UAV swarm-enabled virtual multiple input multiple output(MIMO)system,where multiple single-antenna UAVs cooperatively transmit to multiple ground users(GUs).We establish a common coordinate system,as well as a UAV swarm-oriented coordinate system,to describe the relative positions of the GUs and the UAV elements,respectively.Based on the established coordinate systems,geometric ray superposition method is applied to describe the spatial channel matrix.The proposed modeling framework can be directly used to describe the line-of-sight and two-ray propagations,and can be extended for including more practical spatial features such as multipath scattering,inter-UAV blockage,and random UAV jittering,etc.Based on the proposed model,we further analyze the spatial correlation among the virtual MIMO links of GUs located at different positions.Via extensive simulations,we show that thanks to the flexible deployment of UAVs,the virtual MIMO array structure can be conveniently configured to get desired channel properties,such as the channel capacity,eigenvalue and condition number distribution,and spatial correlation distribution.This shows the possibility and importance of exploiting a new design dimension,i.e.,the UAV swarm pattern,in such cooperative virtual MIMO systems.

关键词： UAV communications MIMO channel model spatical correlation

Assessment of health benefit of PM_(2.5) reduction during COVID-19 lockdown in China and separating contributions from anthropogenic emissions and meteorology

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Journal of Environmental Sciences 2022年第5期34卷 422-431页

作者： Heming Bai Wenkang Gao Yuanpeng Zhang Li Wang research Center for Intelligent Information Technology Nantong UniversityNantong 226019China Nantong Research Institute for Advanced Communication Technologies Nantong 226019China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Department of Medical Informatics Medical SchoolNantong UniversityNantong 226019China

The national lockdown policies have drastically disrupted socioeconomic activities during the COVID-19 pandemic in China,which provides a unique opportunity to investigate the air quality response to such anthropogenic disruptions.And it is meaningful to evaluate the potential health impacts of air quality changes during the lockdown,especially for PM_(2.5) with adverse health effects.In this study,by using PM_(2.5) observations from 1388 monitor-ing stations nationwide in China,we examine the PM_(2.5) variations between the COVID-19 lockdown(February and March in 2020)and the same period in 2015-2019,and find that the national average of PM_(2.5) decreases by 18 μg/m^(3),and mean PM_(2.5) for most sites(about 75%)decrease by 30%-60%.The anthropogenic and meteorological contributions to these PM_(2.5) variations are also determined by using a stepwise multiple linear regression(MLR)model combined with the Kolmogorov-Zurbenko filter.Our results show that the change of anthropogenic emissions is a leading contributor to those widespread PM_(2.5) reductions,and meteorological conditions have the negative influence on PM_(2.5) reductions for some re-gions,such as Beijing-Tianjin-Hebei(BTH).Additionally,the avoided premature death due to PM_(2.5) reduction is estimated as a predicted number based on a log-linear concentration-response function.The total avoided premature death is 9952 in China,with dominant con-tribution(94%)from anthropogenic emission changes.For BTH,Yangtze River Delta,Pearl River Delta and Hubei regions,the reductions of PM_(2.5) are 24.1,24.3,13.5 and 29.5 μg/m^(3),with the avoided premature deaths of 1066,1963,454 and 583,respectively.

关键词： Covid-19 epidemic PM_(2.5) Health benefit Meteorological and anthropogenic contributions KZ filter

RIS-Assisted communications in Correlated Rayleigh Channels:Comparison of Training Overhead Reduction Schemes

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China communications 2022年第12期19卷 41-53页

作者： Jue Wang Shuaifeng Lu Jing Wang Zhenyu Jiang Rui Tang Ruifeng Gao Yingdong Hu Ye Li School of Information Science and Technology Nantong UniversityNantong 226109China Department of Electronic Engineering Tsinghua UniversityBeijing 100084China School of Transportation and Civil Engineering Nantong UniversityNantong 226109China Nantong Research Institute for Advanced Communication Technologies Nantong 226109China

Channel training in reconfigurable intelligent surface(RIS)-assisted communications is usually conducted in an on-off manner,resulting in unaffordable training time overhead when the number of RIS elements is large.In this paper,for correlated Rayleigh channels,we compare three typical training overhead reduction schemes,namely RIS element selection(Scheme 1),element grouping(Scheme 2),and statistical CSI-based phase shifts design(Scheme3).For Scheme 1 and Scheme 2,we propose two algorithms to select RIS elements(or form element groups) and determine the optimal number of activated elements(or formed groups),based on the channel correlation information only;for Scheme 3,we consider a semi-definite programming-based approach in the literature,and propose an alternative dominant eigenvector-based method for determining the RIS phase shifts vector.Via extensive simulations,we compare the achievable ergodic rates of these schemes versus the signal-to-noise ratio,the channel correlation level,and the element number-to-coherent time ratio,respectively,and discuss possible switching of the three schemes over these system parameters.At last,operation regions of the considered training overhead reduction schemes are shown in the plane characterized by the system parameters,which provides useful guidelines for practical scheme determination.

关键词： reconfigurable intelligent surface correlated Rayleigh channel training overhead ergodic achievable rate

Dielectric Patch Resonator and Antenna

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China communications 2023年第8期20卷 209-219页

作者： Jianxin Chen Xueying Wang Shichang Tang Yongle Wu School of Information Science and Technology and Research Center for Intelligent Information TechnologyNantong UniversityNantong 226019China Nantong Research Institute for Advanced Communication Technologies Chongchuan DistrictNantong 226019China School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

This paper presents an overview of dielectric patch(DP)antennas developed in recent years.The employed DP resonator composed of a DP and a bottom substrate is analyzed comprehensively here,enabling the easy realization of a quasi-planar DP antenna.It combines the dual advantages of the conventional microstrip patch(MP)antenna and dielectric resonator(DR)antenna in terms of profile,gain,bandwidth,radiation efficiency,and design freedom.Furthermore,the DP antenna inherits the multi-mode characteristic of the DR antenna,thus it has a large number of high-order modes,including TMmn mode and TEmn mode.The high-order modes are widely applied,for example,by combining with the dominant TM10 mode to expand the bandwidth,or selecting multiple higher-order modes to implement a high-gain antenna.Additionally,the non-radiation high-order modes are also utilized to produce natural radiation null in filtering antenna design.In this paper,the design theories and techniques of DP antenna are introduced and investigated,including calculation and control methods of the resonant mode frequencies,analysis of the radiation mechanism,and applications of the multi-mode characteristic.This overview could provide guidance for the subsequent antenna design,thus effectively avoid time-consuming optimization.

关键词： dielectric patch(DP)resonator DP antenna radiation mechanism multi-mode characteristic

Joint Beamforming and Time Switching Designs for Energy-Constrained Cognitive Two-Way Relay Networks

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China communications 2020年第5期17卷 110-118页

作者： Meijuan Zhang Shibing Zhang Zhihua Bao Wei Wang Xiaoge Zhang Yonghong Chen School of Information Science and Technology Nantong UniversityNantong 226019China nantong research institute for advanced communication Technology Nantong 226019China Xinglin College Nantong UniversityNantong 226019China

In this paper, we investigate a joint beamforming and time switching(TS) design for an energy-constrained cognitive two-way relay(TWR) network. In the network, the energy-constrained secondary user(SU) relay employs TS protocol to harvest energy from the signals sent by the circuit-powered primary user(PU) transmitter, and then exploits the harvested energy to perform information forwarding. Our aim is to maximize the sum rate of SUs under the constraints of the data rate of PU, the energy harvesting and the transmit power of the SU relay. To determine the beamforming matrix and TS ratio, we decouple the original non-convex problem into two subproblems which can be solved by semidefinite relaxation and successive convex optimization methods. Furthermore, we derive closed form expressions of the optimal solutions for each subproblem, which facilitates the design of a suboptimal iterative algorithm to handle the original sum rate maximization problem. Simulation results are presented to illustrate the effectiveness and superior performance of the proposed joint design against other conventional schemes in the literature.

关键词： cognitive networks two-way relay sum rate energy harvesting beamforming