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Multi-antenna UAV Data Harvesting:Joint Trajectory and Communication Optimization

Journal of Communications and Information Networks 2020年第1期5卷 86-99页

作者： Jingwei Zhang Yong Zeng Rui Zhang Department of Electrical and Computer Engineering National University of SingaporeSingapore National Mobile Communications Research Laboratory Southeast UniversityNanjingChina.Purple Mountain LaboratoriesNanjingChina

Unmanned aerial vehicle(UAV)-enabled communication is a promising technology to extend coverage and enhance throughput for traditional terres-trial wireless communication systems.In this paper,we consider a UAV-enabled wireless sensor network,where a Multi-antenna UAV is dispatched to collect data from a group of sensor nodes(SNs).The objective is to maximize the minimum data collection rate from all SNs via jointly optimizing their transmission scheduling and power allocations as well as the trajectory of the UAV,subject to the practical constraints on the maximum transmit power of the SNs and the maximum speed of the UAV.The formulated optimization problem is challenging to solve as it involves non-convex constraints and discrete-value variables.To draw useful insight,we first consider the special case of the formulated problem by ignoring the UAV speed constraint and optimally solve it based on the Lagrange duality method.It is shown that for this relaxed problem,the UAV should hover above a finite number of optimal locations with different durations in general.Next,we address the general case of the formulated problem where the UAV speed constraint is considered and propose a traveling salesman problem-based trajec-tory initialization,where the UAV sequentially visits the locations obtained in the relaxed problem with minimumflying time.Given this initial trajectory,we thenfind the corresponding transmission scheduling and power alloca-tions of the SNs and further optimize the UAV trajectory by applying the block coordinate descent and successive convex approximation techniques.Finally,numerical results are provided to illustrate the spectrum and energy efficiency gains of the proposed scheme for Multi-antenna UAV data harvesting,as compared to benchmark schemes.

关键词： wireless sensor network Multi-antenna unmannedaerialvehicle(UAV) ratemaximization trajectoryoptimization

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Design of Multi-antenna relaying for OFDM in impulsive noise environment

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Digital Communications and Networks 2019年第3期5卷 189-195页

作者： Ahmed El-Mahdy MennaTullah Seraj-Eldin Professor in the Faculty of Information Engineering and Technology German University in Cairo Cairo Egypt The Faculty of Information Engineering and Technology German University in Cairo Cairo Egypt

A low-complexity Multi-antenna relaying scheme is proposed for Orthogonal Frequency Division multiplexing (OFDM) in the presence of Class-A Impulsive Noise (IN). One way and two way relaying are considered. The signal is transmitted and received by two terminal nodes, each with a single antenna in two time phases. In the proposed design, the processing at the relay consists of Maximal-Ratio Combining (MRC) or Power-based Selection Combining (PSC) for receive combining, Amplify and Forward (AF) for power scaling, and Space Time Block Coding (STBC) for transmit diversity. Channel State Information (CSI), Discrete Fourier Transform (DFT), and Inverse Discrete Fourier Transform (IDFT) are not needed. The Selective Mapping (SLM) technique is used at the transmitter to reduce the Peak-to-Average Power Ratio (PAPR) of the OFDM signal. Then, at the receiver, the clipping technique is used to reduce the impulses that result from the impulsive noise. The proposed system reduces the complexity of the conventional system, which uses multi-relay with a single antenna. Simulation results show that the Bit Error Rate (BER) of the proposed scheme outperforms that of the conventional scheme due to the diversity inherent in the proposed scheme.

关键词： Orthogonal frequency division multiplexing Impulsive noise Multi-antenna relay Reception combining Transmit diversity Peak-to-average power ratio reduction techniques

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Non-line-of-sight error mitigating algorithm based on scattering models via Multi-antenna system

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The Journal of China Universities of Posts and Telecommunications 2008年第1期15卷 18-22页

作者： ZHU Xiao-xuan SHI Ming-yang ZHANG Jing TAO Xiao-feng Key Laboratory of Universal Wireless Communications Beijing University of Posts and Telecommunications Ministry of Education Wireless Technology Innovation Institute (WTI) Beijing 100876 China

In urban environment with serious blocking of direct paths, the non-line-of-sight （NLOS） propagation influences the location estimation accuracy. In this article, a novel algorithm is developed, which can mitigate the NLOS errors in location estimation significantly. Utilizing multiantenna array, the information of scatterers that cause the NLOS propagation is obtained. Then, we combine the information with TOA/TDOA based location algorithm to estimate the location of mobile station （MS）. The simulation results show that our method can mitigate NLOS errors and enhance the location accuracy greatly.

关键词： Multi-antenna location algorithm NLOS time of arrival （TOA）

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Adaptive Rate Control for Multi-antenna multicast in OFDM Systems

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Communications and Network 2013年第3期5卷 150-155页

作者： Qinghe Du Pinyi Ren Yi Jia Zhigang Chen School of Electronic and Information Engineering Xi’an Jiaotong University China School of Electronic and Information Engineering Xi’an Jiaotong University China National Mobile Communications Research Laboratory of Southeast University China

We propose two rate control schemes for Multi-antenna multicast in OFDM systems, which aim to maximize the minimum average rate over all users in a multicast group. In our system, we do not require all multicast users to successfully recover the signals received on each subcarrier. In contrast, we allow certain loss for multicast users, such that the multicast transmission rate can be increased. We assume that the loss-repairing can be completed at upper protocol layers via advanced fountain codes. Following this principle, we formulate the rate control problem via beamforming in Multi-antenna multicast to optimize the minimum achievable rate for all multicast users. While the computation complexity to solve for the optimal beamformer is prohibitively high, we propose a suboptimal iterative rate control scheme. Moreover, we modify the above optimization problem by selecting a ?xed proportion of users on each subcarrier. The beamformer searching process will then be performed only based on the selected users on each subcarrier, such that the complexity can be further reduced. We also solve this new problem with a low complexity approach. Theoretical analyses and simulation results show that our proposed two rate control schemes can have higher minimum average rate than the baseline scheme without rate control, while achieving low complexity.

关键词： multicast OFDM Multi-antenna Rate Control

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A physical layer security scheme for full-duplex communication systems with residual self-interference and non-eavesdropping CSI

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Digital Communications and Networks 2021年第3期7卷 352-361页

作者： Weijia Lei Yang Zhou Xiuzhen Lin School of Communication and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing400065China

We discuss the physical layer security scheme in the Full-Duplex(FD)MIMO point-to-point two-way communication system with residual self-interference,in which legitimate nodes send confidential information and null space Artificial Noise(AN)while receiving information.Because the Channel State Information(CSI)of the eavesdropper is unavailable,we optimize the covariance matrices of the information signal as well as the allocation of the antenna for transmitting and receiving to minimize the signal power consumption under the target rate constraint.As a result,the power of AN is maximized within the limit of total power,so the interception capability of the eavesdropper is suppressed as much as possible.Since self-interference cannot be completely eliminated,the optimization process of one legitimate node depends on the optimization result of the other.By substituting self-interference power in the secrecy rate formula with its average value,the joint optimization process at the two nodes is transformed into two separate and solvable optimization processes.Then,the Water-Filling Algorithm(WFA)and bisection algorithm are used to get the optimal covariance matrices of the signal.Furthermore,we derive the theoretical lower bound of ergodic achievable secrecy rate under rayleigh channels to evaluate the performance of the scheme.The simulation results show that the theoretical derivation is correct,and the actual achievable rate is very close to the target rate,which means that the approximation in the optimization is feasible.The results also show that secrecy transmission can be realized because a considerable secrecy rate can be achieved.

关键词： Physical layer security Full-duplex Self-interference Eavesdropping CSI Multi-antenna

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Two-step transmission with artificial noise for secure wireless SIMO communications

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Science China(Information Sciences) 2015年第4期58卷 115-127页

作者： WANG Bo MU PengCheng YANG PeiZhi YIN QinYe Ministry of Education Key Lab for Intelligent Networks and Network Security School of Electronic and Information Engineering Xi’an Jiaotong University

The issue of physical layer security of the wireless single-input multiple-output(SIMO) system is addressed in this paper. We propose a two-step transmission scheme with artificial noise to improve the security and the scheme does not require the channel state information of the eavesdropper. In the first step, the destination which has multiple antennas generates a random reference symbol and artificial noise and transmits them in the direction of the source and its orthogonal space, respectively. The reference symbol is received by the source without being polluted by the artificial noise, while it is jammed by the artificial noise for the eavesdropper. In the second step, the symbol of the source is multiplied by the received reference symbol and then transmitted. Finally, the destination can directly estimate the symbol of the source using the reference symbol. However, the eavesdropper needs to additionally estimate the reference symbol for demodulating the symbol of the source, which usually obtains an inaccurate result due to the artificial noise. The informationtheoretic security of our scheme is analyzed and a lower bound of the achievable secrecy rate is derived. The performance of the new scheme is compared with that of the traditional approach under different input signals through numerical simulations. The results show that the proposed scheme outperforms the traditional SIMO approach especially in the high SNR region.

关键词： wireless communication physical layer security Multi-antenna SIMO artificial noise

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An optimized non-unitary linear precoding design for OSTBCs

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Science China(Information Sciences) 2010年第2期53卷 335-343页

作者： HUANG HaiYang , WU Gang, LU Lu & LI ShaoQian National Key Laboratory of Communications, University of Electronic Science and Technology of China, Chengdu 610054, China National Key Laboratory of Communications University of Electronic Science and Technology of China Chengdu China

This paper tackles the optimization of non-unitary linear precoding design for orthogonal spacetime block codes (OSTBCs). We dig out the transmission potentials by the analysis from eigen-space point of view according to the unique structure of OSTBCs. The proposed precoding form is proven to be theoretically optimized. Compared with the classical unitary Grassmannian codebook design, the non-unitary codebook further improves the overall performance of practical systems. The constraint on codebook size to guarantee full diversity order is given and proven. Based on this, we investigate the codebook construction method combined with a water-filling (WF) technique to reduce the impact of antenna correlation. The advantages of the novel design are verified via numerical simulations.

关键词： Multi-antenna linear precoding OSTBCs non-unitary design antenna correlation

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A Review of Enabling Physical-Layer Technologies for Terahertz Communications

A Review of Enabling Physical-Layer Technologies for Teraher...

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第40届中国控制会议

作者： Haiyao Xie Feifei Wang Yihao Zhang Shanping Yu Shuo Chen School of Information and electronics Beijing Institute of Technology School of Electronic Engineering and Computer Science Peking University Innovation Laboratory of Terahertz Biophysics National Innovation Institute of Defense Technology

With the explosive growth of mobile data demand,the contradiction between rate demand and spectrum shortage has become increasingly prominent.High-frequency communication systems such as millimeter wave and terahertz have gradually entered people/s field of vision,and they have been applied to satellite communications because of their vast bandwidth.The bottleneck of wireless bandwidth and spectrum utilization has become a vital issue for future wireless mobile networks,so terahertz communication has been proposed as an essential part of 5G and future 6G mobile networks.This article mainly investigates the enabling physical layer’s critical technologies under the background of terahertz communication,including the recent research and development trend of the high-frequency band and Multi-antenna technology and coding technology.Finally,this article points out the challenges and research directions of the terahertz communication network’s physical layer technology in the future.

关键词： Terahertz Technology Communication Networks Physical Layer Technology Coding Technology High-frequency transmission Multi-antenna

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Continuous Monitoring of Landslide and Atmospheric Water Vapor Using GPS:Application in Pubugou Hydropower Resettlement Zone

Continuous Monitoring of Landslide and Atmospheric Water Vap...

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第三届中国卫星导航学术年会

作者： XIAO Ruya,HE Xiufeng,LI Linhong Institute of Satellite Navigation and Spatial Information System,Hohai University

Resettlement is one of the most important major issues of the hydropower development.Based on GPS Multi-antenna,wireless bridge,3rd Generation telecommunication technologies and single epoch solution algorithm,a near real-time landslide monitoring system of Pubugou hydropower engineering resettlement zone,new Hanyuan County,is under construction.GPS has also been proven an effective mean to detect atmospheric water vapor and the precipitable water （PW） over the new town was obtained.Results show the GPS system provides deformation with 3-4mm accuracy which can meet the requirements of landslide monitoring and the atmospheric water vapor changes is useful and meaningful to precipitation forecast as well as the landslide early warning system.

关键词： resettlement zone landslide monitoring GPS Multi-antenna near real-time precipitable water

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Joint User and antenna Selection for multiuser MIMO Downlink with Block Diagonalization

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Journal of Shanghai Jiaotong university(Science) 2011年第6期16卷 691-695页

作者：刘伟邹俊罗汉文马继鹏 Department of Electronic Engineering Shanghai Jiaotong University State Key Laboratory of Wireless Communications China Academy of Telecommunications Technology Leadcore Technology Co. Ltd.

User selection is necessary for multiuser multiple-input multiple-output(MIMO) downlink systems with block diagonalization(BD) due to the limited free spatial transmit dimensions.The pure user selection algorithms can be improved by performing receive antenna selection(RAS) to increase sum rate.In this paper,a joint user and antenna selection algorithm,which performs user selection for sum rate maximization in the first stage and then performs antenna selection in the second stage,is proposed.The antenna selection process alternately drops one antenna with the poorest channel quality based on maximum determinant ranking(MDR) from the users selected during the first stage and activates one antenna with the maximum norm of projected channel from the remaining users.Simulation results show that the proposed algorithm significantly outperforms the algorithm only performing user selection as well as the algorithm combining user selection with MDR receive antenna selection in terms of sum rate.

关键词： multiuser multiple-input multiple-output(MIMO) Multi-antenna block diagonalization(BD) joint user and antenna selection

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