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Learning-based user association and dynamic resource allocation in multi-connectivity enabled unmanned aerial vehicle networks

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Digital communications and Networks 2024年第1期10卷 53-62页

作者： Zhipeng.Cheng.Minghui Liwang Ning Chen Lianfen Huang Nadra Guizani Xiaojiang Du Department of Information and communication eng.neering Xiamen UniversityXiamen361005China School of Electrical and Computer eng.neering University of Texas at ArlingtonArlingtonTX76019USA Department of Electrical and Computer eng.neering Stevens Institute of TechnologyHobokenNJ07030USA

Unmanned Aerial Vehicles(UAvs)as aerial base stations to provide communication services for ground users is a flexible and cost-effective paradigm in ***,dynamic resource allocation and multi-connectivity can be adopted to further harness the potentials of UAVs in improving communication capacity,in such situations such that the interference among users becomes a pivotal disincentive requiring effective *** this end,we investigate the Joint UAV-User Association,Channel Allocation,and transmission Power Control(J-UACAPC)problem in a multi-connectivity-enabled UAV network with constrained backhaul links,where each UAV can determine the reusable channels and transmission power to serve the selected ground *** goal was to mitigate co-channel interference while maximizing long-term system *** problem was modeled as a cooperative stochastic game with hybrid discrete-continuous action space.A Multi-Agent Hybrid Deep Reinforcement Learning(MAHDRL)algorithm was proposed to address this *** simulation results demonstrated the effectiveness of the proposed algorithm and showed that it has a higher system utility than the baseline methods.

关键词： UAV-user association Multi-connectivity Resource allocation Power control Multi-agent deep reinforcement learning

Analysis of phase preservation and interferometric offset test in sparse SAR imaging

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Science China(Information Sciences) 2024年第2期67卷 219-231页

作者： Zhongqiu XU Bingchen ZHANG Guangzuo LI Xueli ZHAN Yanfei BAO Yirong WU Key Laboratory of Spatial Information Processing and Application System Technology Chinese Academy of Sciences Aerospace Information Research institute Chinese Academy of Sciences School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of Sciences PLA Academy of Military Sciences

Sparse synthetic aperture radar(SAR) imaging has emerged as a reliable microwave imaging scheme in the recent decade and excels in down-sampling reconstruction and full-sampling performance improvements such as noise, sidelobe, speckle, and ambiguity suppression. To utilize complex image products of sparse reconstruction for improvement in polarimetric, interferometric, and tomographic SAR imaging, it is necessary to evaluate the phase preservation of sparse SAR imaging. In this study, we first introduce the general alternating direction method of multipliers(ADMM) as the universal framework for sparse reconstruction algorithms and adopt chirp scaling algorithm(CSA)-based azimuth-range decouple operators to avoid expensive data storage and processing. Further, we theoretically analyze the phase preservation of the sparse reconstruction algorithm through a comparison with the reconstruction results of CSA. Finally,we conduct the interferometric offset test on the sparse reconstruction results of simulated and real Gaofen-3(GF-3) SAR data, demonstrating the phase-preserving ability of sparse methods.

关键词： sparse SAR imaging phase preservation interferometric offset test general ADMM azimuth-range decouple

Atomic transport dynamics in crossed optical dipole trap

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Chinese Physics B 2024年第7期33卷 293-301页

作者：彭鹏张正熙樊耀塬殷国玲毛德凯陈徐宗熊炜周小计 State Key Laboratory of Advanced Optical communication System and Network School of ElectronicsPeking UniversityBeijing 100871China institute of Carbon-based Thin Film Electronics Peking UniversityTaiyuan 030012China State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-ElectronicsShanxi UniversityTaiyuan 030006China

We study the dynamical evolution of cold atoms in crossed optical dipole trap theoretically and experimentally. The atomic transport process is accompanied by two competitive kinds of physical mechanics, atomic loading and atomic *** loading process normally is negligible in the evaporative cooling experiment on the ground, while it is significant in preparation of ultra-cold atoms in the space station. Normally, the atomic loading process is much weaker than the atomic loss process, and the atomic number in the central region of the trap decreases monotonically, as reported in previous research. However, when the atomic loading process is comparable to the atomic loss process, the atomic number in the central region of the trap will initially increase to a maximum value and then slowly decrease, and we have observed the phenomenon first. The increase of atomic number in the central region of the trap shows the presence of the loading process, and this will be significant especially under microgravity conditions. We build a theoretical model to analyze the competitive relationship, which coincides with the experimental results well. Furthermore, we have also given the predicted evolutionary behaviors under different conditions. This research provides a solid foundation for further understanding of the atomic transport process in traps. The analysis of loading process is of significant importance for preparation of ultra-cold atoms in a crossed optical dipole trap under microgravity conditions.

关键词： cold atom crossed optical dipole trap transport process

High performance receiving and processing technology in satellite beam hopping communication

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Journal of Systems eng.neering and Electronics 2024年第4期35卷 815-828页

作者： ZHAI Sheng.ua HUI Teng.ei GONG Xianfeng.ZHANG Zehui GAO Xiaozheng.YANG Kai School of communication eng.neering Xi’Dian UniversityXian 710126China CAST(China Academy of Space Technology)-Xi’an institute of Space Radio Technology Xi’an 710010China School of Cyberspace Science and Technology Beijing Institute of TechnologyBeijing 100081China School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China

Beam-hopping technology has become one of the major research hotspots for satellite communication in order to enhance their communication capacity and ***,beam hopping causes the traditional continuous time-division multiplexing signal in the forward downlink to become a burst signal,satellite terminal receivers need to solve multiple key issues such as burst signal rapid synchronization and high-per-formance ***,this paper analyzes the key issues of burst communication for traffic signals in beam hopping sys-tems,and then compares and studies typical carrier synchro-nization algorithms for burst ***,combining the requirements of beam-hopping communication systems for effi-cient burst and low signal-to-noise ratio reception of downlink signals in forward links,a decoding assisted bidirectional vari-able parameter iterative carrier synchronization technique is pro-posed,which introduces the idea of iterative processing into car-rier *** at the technical characteristics of communication signal carrier synchronization,a new technical approach of bidirectional variable parameter iteration is adopted,breaking through the traditional understanding that loop struc-tures cannot adapt to low signal-to-noise ratio burst ***,combining the DVB-S2X standard physical layer frame format used in high throughput satellite communication systems,the research and performance simulation are *** results show that the new technology proposed in this paper can significantly shorten the carrier synchronization time of burst signals,achieve fast synchronization of low signal-to-noise ratio burst signals,and have the unique advantage of flexible and adjustable parameters.

关键词： beam-hopping high throughput satellite high per-formance reception processing

Power Allocation for SE Maximization in Uplink Massive MIMO System Under Minimum Rate Constraint

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China communications 2024年第3期21卷 104-117页

作者： Wang Hui Yu Xiangbin Liu Fuyuan Bai Jiawei College of Electronic and Information eng.neering Nanjing University of Aeronautics and AstronauticsNanjing 211106China Key Laboratory of Wireless Sensor Network and communication Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China

In this paper,we optimize the spectrum efficiency(SE)of uplink massive multiple-input multiple-output(MIMO)system with imperfect channel state information(CSI)over Rayleigh fading *** SE optimization problem is formulated under the constraints of maximum power and minimum rate of each ***,we develop a near-optimal power allocation(PA)scheme by using the successive convex approximation(SCA)method,Lagrange multiplier method,and block coordinate descent(BCD)method,and it can obtain almost the same SE as the benchmark scheme with lower *** this scheme needs three-layer iteration,a suboptimal PA scheme is developed to further reduce the complexity,where the characteristic of massive MIMO(i.e.,numerous receive antennas)is utilized for convex reformulation,and the rate constraint is converted to linear *** suboptimal scheme only needs single-layer iteration,thus has lower complexity than the near-optimal ***,we joint design the pilot power and data power to further improve the performance,and propose an two-stage algorithm to obtain joint *** results verify the effectiveness of the proposed schemes,and superior SE performance is achieved.

关键词： imperfect CSI massive MIMO minimum rate constraint power allocation spectral efficiency

The Criteria for Reducing Centrally Restricted Three-Body Problem to Two-Body Problem

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International Journal of Astronomy and Astrophysics 2024年第1期14卷 1-19页

作者： Bijay Kumar Sharma Department of Electronics and communication National Institute of Technology Patna India

Our Solar System contains eight planets and their respective natural satellites excepting the inner two planets Mercury and Venus. A satellite hosted by a given Planet is well protected by the gravitational pertubation of much heavier planets such as Jupiter and Saturn if the natural satellite lies deep inside the respective host Planet Hill sphere. Each planet has a Hill radius aH and planet mean radius RP and the ratio R1=RP/aH. Under very low R1 (less than 0.006) the approximation of CRTBP (centrally restricted three-body problem) to two-body problem is valid and planet has spacious Hill lobe to capture a satellite and retain it. This ensures a high probability of capture of natural satellite by the given planet and Sun’s perturbation on Planet-Satellite binary can be neglected. This is the case with Earth, Mars, Jupiter, Saturn, Neptune and Uranus. But Mercury and Venus has R1=RP/aH =0.01 and 5.9862 × 10-3 respectively hence they have no satellites. There is a limit to the dimension of the captured body. It must be a much smaller body both dimensionally as well masswise. The qantitative limit is a subject of an independent study.

关键词： Hill’s Radius Two-Body Problem Fixed-Point Solution Lagrange Points Earth-Moon-Test Particle CRTBP

Face animation based on multiple sources and perspective alignment

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虚拟现实与智能硬件（中英文） 2024年第3期6卷 252-266页

作者： Yuanzong MEI Wenyi WANG Xi LIU Wei YONG Weijie WU Yifan ZHU Shuai WANG Jianwen CHEN School of Information and communication eng.neering University of Electronic Science and Technology of ChinaChengdu 611731China Yangtze Delta Region institute(Quzhou) University of Electronic Science and Technology of ChinaQuzhou 324000China

Background Face image animation generates a synthetic human face video that harmoniously integrates the identity derived from the source image and facial motion obtained from the driving *** technology could be beneficial in multiple medical fields,such as diagnosis and privacy *** studies on face animation often relied on a single source image to generate an output *** a significant pose difference between the source image and the driving frame,the quality of the generated video is likely to be suboptimal because the source image may not provide sufficient features for the warped feature *** In this study,we propose a novel face-animation scheme based on multiple sources and perspective alignment to address these *** first introduce a multiple-source sampling and selection module to screen the optimal source image set from the provided driving *** then propose an inter-frame interpolation and alignment module to further eliminate the misalignment between the selected source image and the driving *** The proposed method exhibits superior performance in terms of objective metrics and visual quality in large-angle animation scenes compared to other state-of-the-art face animation *** indicates the effectiveness of the proposed method in addressing the distortion issues in large-angle animation.

关键词： Face animation Multiple-source driving Generative adversarial network Medical diagnostics

Bifurcations,chaos analysis and control in a discrete predator-prey model with mixed functional responses

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International Journal of Biomathematics 2024年第3期17卷 185-210页

作者： Yajie Sun Ming Zhao Yunfei Du School of Science China University of Geosciences(Beijing)Beijing100083P.R.China School of Basic Education Beijing institute of Graphic communication Beijing102600P.R.China

Many discrete systems have more distinctive dynamical behaviors compared to continuous ones,which has led lots of researchers to investigate *** discrete predatorprey model with two different functional responses(Holling type I and II functional responses)is discussed in this paper,which depicts a complex population *** local dynamical behaviors of the interior fixed point of this system are *** detailed analysis reveals this system undergoes flip bifurcation and Neimark-Sacker ***,we prove the existence of Marotto's chaos by analytical *** addition,the hybrid control method is applied to control the chaos of this *** simulations are presented to support our research and demonstrate new dynamical behaviors,such as period-10,19,29,39,48 orbits and chaos in the sense of Li-Yorke.

关键词： Predator-prey model flip bifurcation Neimark-Sacker bifurcation Marotto's chaos chaos control

WSN Mobile Target Tracking Based on Improved Snake-Extended Kalman Filtering Algorithm

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Journal of Beijing institute of Technology 2024年第1期33卷 28-40页

作者： Duo Peng.Kun Xie Mingshuo Liu School of Computer and communication of Lanzhou University of Technology Lanzhou Gansu 730050China

A wireless sensor network mobile target tracking algorithm(ISO-EKF)based on improved snake optimization algorithm(ISO)is proposed to address the difficulty of estimating initial values when using extended Kalman filtering to solve the state of nonlinear mobile target ***,the steps of extended Kalman filtering(EKF)are ***,the ISO is used to adjust the parameters of the EKF in real time to adapt to the current motion state of the mobile ***,the effectiveness of the algorithm is demonstrated through filtering and tracking using the constant velocity circular motion model(CM).Under the specified conditions,the position and velocity mean square error curves are compared among the snake optimizer(SO)-EKF algorithm,EKF algorithm,and the proposed *** comparison shows that the proposed algorithm reduces the root mean square error of position by 52%and 41%compared to the SOEKF algorithm and EKF algorithm,respectively.

关键词： wireless sensor network(WSN)target tracking snake optimization algorithm extended Kalman filter maneuvering target