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A Dual-Cluster-Head Based Medium Access Control for Large-Scale UAV Ad-Hoc Networks

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China communications 2024年第5期21卷 123-136页

作者： Zhao Xinru Wei Zhiqing Zou Yingying Ma Hao Cui Yanpeng Feng Zhiyong key laboratory of universal wireless communications Ministry of EducationSchool of Information and Communication EngineeringBeijing University of Posts and TelecommunicationsBeijing100876China

Unmanned Aerial Vehicle(UAV)ad hoc network has achieved significant growth for its flexibility,extensibility,and high deployability in recent years.The application of clustering scheme for UAV ad hoc network is imperative to enhance the performance of throughput and energy efficiency.In conventional clustering scheme,a single cluster head(CH)is always assigned in each cluster.However,this method has some weaknesses such as overload and premature death of CH when the number of UAVs increased.In order to solve this problem,we propose a dual-cluster-head based medium access control(DCHMAC)scheme for large-scale UAV networks.In DCHMAC,two CHs are elected to manage resource allocation and data forwarding cooperatively.Specifically,two CHs work on different channels.One of CH is used for intra-cluster communication and the other one is for inter-cluster communication.A Markov chain model is developed to analyse the throughput of the network.Simulation result shows that compared with FM-MAC(flying ad hoc networks multi-channel MAC,FM-MAC),DCHMAC improves the throughput by approximately 20%~50%and prolongs the network lifetime by approximately 40%.

关键词： dual cluster head medium access control UAV swarm

Emergency access mechanism in IEEE 802.15.4 for wireless body area sensor networks

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The Journal of China Universities of Posts and Telecommunications 2009年第6期16卷 24-31页

作者： GUO Yan-yan,KANG Gui-xia,CAO Yu,ZHANG Ping key laboratory of universal wireless communications,ministry of education,Beijing University of Posts and Telecommunications,Beijing 100876,China key laboratory of universal wireless communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

IEEE 802.15.4 protocol has attracted much attention in research and industrial communities as candidate technology for wireless body area sensor networks（WBASNs）.IEEE 802.15.4 supports the exclusive use of a wireless channel through guaranteed time slot（GTS）.However,on one hand,bandwidth underutilization rate may be lower because of the variance between the guaranteed bandwidth and the arrival rate.On the other hand,the waiting time for transmitting emergency notification is getting longer when the GTSs assigned to the nodes increase in WBASNs.To solve these problems,in this article,a new scheme is proposed to reduce transmission delay for the alarm notification in emergent situations.Simulation results are presented to validate the efficiency of the proposed scheme by comparing it with the medium access control（MAC） protocol of IEEE 802.15.4.

关键词： WBASN GTS IEEE 802.15.4 emergency mechanism

Semantic information processing for interoperability in the Industrial Internet of Things

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Fundamental Research 2024年第1期4卷 8-12页

作者： Shengshi Yao Yanpeng Lu Kai Niu Jincheng Dai Chao Dong Ping Zhang key laboratory of universal wireless communications Ministry of EducationBeijing University of Posts and TelecommunicationsBeijing 100876China The State key laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

With the advent of the Internet of Everything(IoE),the concept of fully interconnected systems has become a reality,and the need for seamless communication and interoperability among different industrial systems has become more pressing than ever before.To address the challenges posed by massive data traffic,we demonstrate the potentials of semantic information processing in industrial manufacturing processes and then propose a brief framework of semantic processing and communication system for industrial network.In particular,the scheme is featured with task-orientation and collaborative processing.To illustrate its applicability,we provide examples of time series and images,as typical industrial data sources,for practical tasks,such as lifecycle estimation and surface defect detection.Simulation results show that semantic information processing achieves a more efficient way of information processing and exchanging,compared to conventional methods,which is crucial for handling the demands of future interconnected industrial networks.

关键词： Semantic communication Intelligent manufacturing Signal processing Industrial Internet Task-oriented communication

Spectral efficient half-duplex relaying with interference suppression

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The Journal of China Universities of Posts and Telecommunications 2010年第6期17卷 19-24页

作者： LI Xing-zheng,LIU Yuan-an,XIE Gang,CHANG Ling-jun,HAN Xiao key laboratory of universal wireless communications,ministry of education,Beijing University of Posts and Telecommunications,Beijing 100876,China key laboratory of universal wireless communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

Two-hop relaying systems suffer spectral efficiency loss due to the half-duplex property of relays. This paper proposes an efficient relaying protocol which can recover the spectral efficiency loss but still work with half-duplex relays. However,there exists inter-relay interference which degrades the performance of the protocol. With this consideration,a power control policy is derived to suppress the interference using game theory,and then an algorithm is given to facilitate distributed implementation. Furthermore,impact of deploying more destination antennas on performance of the relaying protocol is investigated. Simulation results show that,with the power control policy,the proposed relaying protocol can achieve high spectral efficiency.

关键词： relaying protocol distributed power control cooperative communication decode-and-forward relay game theory

Cross layer scheduling for real-time traffic in multiuser MIMO-OFDMA systems

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The Journal of China Universities of Posts and Telecommunications 2009年第3期16卷 24-29页

作者： SUN Qiao-yun,TIAN Hui,DONG Kun,ZHANG Ping key laboratory of universal wireless communications,ministry of education,Beijing University of Posts and Telecommunications,Beijing 100876,China key laboratory of universal wireless communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

A novel cross layer scheduling algorithm is proposed for real-time （RT） traffic in multiuser downlink multiple-input multiple-output orthogonal frequency division multiple access （MIMO-OFDMA） wireless systems. The algorithm dynamically allocates resources in space, time and frequency domain based on channel state information （CSI）, users＇ quality of service （QoS） requirements and queue state information （QSI）. To provide higher data rate and spectrum efficiency, adaptive modulation and coding （AMC） is employed. The proposed algorithm can improve cell throughput and increase the number of users that can be supported while guaranteeing users＇ QoS requirements and fairness among all users. Simulation results indicate that the proposed algorithm can achieve superior performance.

关键词： MIMO-OFDMA cross layer QoS AMC

On the bounds of frequency-selective channel capacity with doubly correlated geometrical MIMO channel model

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The Journal of China Universities of Posts and Telecommunications 2010年第2期17卷 8-13页

作者： LI Yong-hua , Lü Tie-jun, WU Xiao-fei, ZHANG Lin key laboratory of universal wireless communications, ministry of education, Beijing University of Posts and Telecommunications, Beijing 100876, China key laboratory of universal wireless communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

The multi-input multi-output （MIMO） technology plays an important role in link transmissions. This article considers the general case for the ergodic capacity in doubly correlated frequency-selective MIMO channel. In the study, the geometrical MIMO channel model is presented. Based on the formula of MIMO ergodic capacity, the capacity limits are studied with arbitrary finite number of antennas in the frequency-selective MIMO channel. It first derives the exact expressions for the upper bound and lower bound in doubly correlated MIMO channel. The results for the single-ended correlation and independent identically distributed （i.i.d.） MIMO channel are also obtained as special cases. Then the simple expressions of the capacity bounds are attained at high SNR. Finally, results are provided by Monte Carlo simulations to verify the tightness of the derived bounds.

关键词： MIMO correlation capacity bounds

Bandwidth allocation and admission control scheme based on Nash bargaining solution for WiMAX systems

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The Journal of China Universities of Posts and Telecommunications 2010年第2期17卷 53-58页

作者： CAI Dao-jin ,JI Hong,LI Xi key laboratory of universal wireless communications,ministry of education,Beijing University of Posts and Telecommunications,Beijing 100876,China key laboratory of universal wireless communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

Development of fair and efficient bandwidth allocation and admission control schemes is one of the key issues in the design of IEEE 802.16 broadband wireless access systems in time division multiple access （TDMA） mode. In this article, the problem of bandwidth allocation and admission control is formulated as a Nash bargaining model. The nash bargaining solution （NBS） derived from the cooperative game is adopted to maximize the spectrum utilization. Analysis and simulation results show that there is a unique Pareto optimal bandwidth allocation solution by using NBS among various flows. Furthermore, maximum utility of the system can also be maintained by using the admission control policy with different number of connections and variable channel qualities. The total throughput of the proposed scheme is close to the maximal one, while significantly improving fairness compared to the existing solutions.

关键词： NBS game theory bandwidth allocation admission control IEEE 802.16

Hopping control channel MAC protocol for opportunistic spectrum access networks

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The Journal of China Universities of Posts and Telecommunications 2010年第6期17卷 65-71页

作者： FU Jing-tuan,JI Hong,MAO Xu key laboratory of universal wireless communications,ministry of education,Beijing University of Posts and Telecommunications,Beijing 100876,China key laboratory of universal wireless communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

Opportunistic spectrum access （OSA） is considered as a promising approach to mitigate spectrum scarcity by allowing unlicensed users to exploit spectrum opportunities in licensed frequency bands. Derived from the existing channel-hopping multiple access （CHMA） protocol,we introduce a hopping control channel medium access control （MAC） protocol in the context of OSA networks. In our proposed protocol,all nodes in the network follow a common channel-hopping sequence; every frequency channel can be used as control channel and data channel. Considering primary users＇ occupancy of the channel,we use a primary user （PU） detection model to calculate the channel availability for unlicensed users＇ access. Then,a discrete Markov chain analytical model is applied to describe the channel states and deduce the system throughput. Through simulation,we present numerical results to demonstrate the throughput performance of our protocol and thus validate our work.

关键词： channel hopping MAC protocol OSA Markov chain

Robust Tomlinsion-Harashima precoding design with outdated CSIT

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The Journal of China Universities of Posts and Telecommunications 2010年第2期17卷 59-62页

作者： WANG Xu-zhen ,NIU Kai,HE Zhi-qiang,YU Guang-wei,WU Wei-ling key laboratory of universal wireless communications,ministry of education,Beijing University of Posts and Telecommunications,Beijing 100876,China key laboratory of universal wireless communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

The channel state information at transmitter （CSIT） acquisition plays a key role in the multi-input multi-output （MIMO） system, especially for the precoding schemes. However it is unrealizable to acquire perfect CSIT in practice. In this article, an effective and practical dynamic CSIT model is introduced to acquire imperfect channel state information. For practicability, the channel temporal and spatial correlations are considered and the channel estimate and its error covariance are obtained by utilizing the outdated channel state information. Based on the dynamic CSIT mode, closed-form solution of robust Tomlinsion-Harashima precoding （THP） is derived by a Lagrangian approach. Numerical simulations are presented to demonstrate the performance.

关键词： channel estimation imperfect CSIT robust THP