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QoE-Driven Social Aware Caching Placement for Terrestrial-Satellite Networks

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China Communications 2018年第10期15卷 60-72页

作者： Guiting Zhong Jian Yan linling kuang Tsinghua Space Center Tsinghua University Beijing 100084 China Beijing National Research Center for Information Science and Technology China

In remote terrestrial-satellite networks, caching is a very promising technique to alleviate the burden of space cloudlet(e.g., cache-enabled satellite user terminal) and to improve subscribers' quality of experience(Qo E) in terms of buffering delay and achievable video streaming rate. In this paper, we studied a Qo E-driven caching placement optimization problem for video streaming that takes into account the required video streaming rate and the social relationship among users. Social ties between users are used to designate a set of helpers with caching capability, which can cache popular files proactively when the cloudlet is idle. We model the utility function of Qo E as a logarithmic function. Then, the caching placement problem is formulated as an optimization problem to maximize the user's average Qo E subject to the storage capacity constraints of the helpers and the cloudlets. Furthermore, we reformulate the problem into a monotone submodular optimization problem with a partition matroid constraint, and an efficient greedy algorithm with 1-1 e approximation ratio is proposed to solve it. Simulation results show that the proposed caching placement approach significantly outperforms the traditional approaches in terms of Qo E, while yields about the same delay and hit ratio performance compare to the delay-minimized scheme.

关键词： quality of experience (QoE) caching placement terrestrial-satellite networks submodular optimization social awareness

Beam Scheduling with Various Mission Demands in Data Relay Satellite Systems

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Journal of Communications and Information Networks 2021年第4期6卷 396-410页

作者： Boyu Deng Chunxiao Jiang Jingchao Wang linling kuang The Department of Electronic Engineering Tsinghua UniversityBeijing 100084China Tsinghua Space Center Tsinghua UniversityBeijing 100084China Peng Cheng Laboratory Shenzhen 518055China

Beam scheduling is one of the most important issues regarding data relay satellite systems,which can improve the utilization efficiency of limited system resources by programming beam allocation for relay *** ever-increasing relay missions create a substantial challenge for beam scheduling due to an increase in different mission *** cooperative usage of different beams further increases the complexity of this ***,we develop a novel optimization method to solve the beam scheduling problem for the scenario of various mission demands in the data relay satellite system(DRSS).Based on the analysis of mission demands and resource features,we first construct a heterogeneous parallel machines scheduling model to formulate the beam scheduling problem in the *** solve this complicated model,we investigate the matching method between mission demands and beam resources,and introduce two concepts,the loose duration and the number of available beams,to make the matching process more ***,the following three algorithms are *** first approach,the maximized completion probability algorithm(MCPA),applies a greedy strategy based on the new concepts to allocate beams for missions;and two improved versions of this algorithm are also presented,which employ the strategies of mission insertion optimization and mission sequence optimization,*** simulation results show that the proposed algorithms are superior to the existing algorithms in terms of the scheduled missions,the weight of scheduled missions,and the processing time,which significantly improves the performance of beam scheduling in the DRSS.

关键词： DRSS beam scheduling various mission demands loose duration available beams greedy algorithm

Low-Complexity Joint Channel Estimation and Symbol Detection for OFDMA Systems

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China Communications 2019年第7期16卷 49-60页

作者： Rui Xin Zuyao Ni Sheng Wu linling kuang Chunxiao Jiang Department of Aerospace Engineering Tsinghua University Beijing 100084 China Tsinghua Space Center Tsinghua University Beijing 100084 China Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China Beijing National Research Center for Information Science and Technology Beijing 100084 China

In this paper,we propose a joint channel estimation and symbol detection(JCESD)algorithm relying on message-passing algorithms(MPA)for orthogonal frequency division multiple access(OFDMA)*** channel estimation and symbol detection leverage the framework of expectation propagation(EP)and belief propagation(BP)with the aid of Gaussian approximation,***,to reduce the computation complexity involved in channel estimation,the matrix inversion is transformed into a series of diagonal matrix inversions through the Sherman-Morrison *** experiments show that the proposed algorithm can reduce the pilot overhead by about 50%,compared with the traditional linear minimum mean square error(LMMSE)algorithm,and can approach to the bit error rate(BER)performance bound of perfectly known channel state information within 0.1 dB.

关键词： joint channel estimation and symbol detection message passing OFDMA

Adaptive subsequence adjustment with evolutionary asymmetric path-relinking for TDRSS scheduling

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Journal of Systems Engineering and Electronics 2014年第5期25卷 800-810页

作者： Peng Lin linling kuang Xiang Chen Jian Yan Jianhua Lu Xiaojuan Wang Department of Electronic Engineering Tsinghua University China Electronic Equipment of System Engineering Institute Tsinghua Space Center Tsinghua University

Due to the limited transmission resources for data relay in the tracking and data relay satellite system （TDRSS）, there are many job requirements in busy days which will be discarded in the conventional job scheduling model. Therefore, the improvement of scheduling efficiency in the TDRSS can not only help to increase the resource utilities, but also to reduce the scheduling failure ratio. A model of nonhomogeneous parallel machines scheduling problems with time window （NPM-TW） is firstly built up for the TDRSS, considering the distinct features of the variable preparation time and the nonhomogeneous transmission rates for different types of antennas on each tracking and data relay satellite （TDRS）. Then, an adaptive subsequence adjustment （ASA） framework with evolutionary asymmetric path-relinking （EvAPR） is proposed to solve this problem, in which an asymmetric progressive crossover operation is involved to overcome the local optima by the conventional job inserting methods. The numerical results show that, compared with the classical greedy randomized adaptive search procedure （GRASP） algorithm, the scheduling failure ratio of jobs can be reduced over 11% on average by the proposed ASA with EvAPR.

关键词： nonhomogeneous parallel machines scheduling problem with time window (NPM-TW) adaptive subsequence adjustment (ASA) asymmetric path-relinking (APR) evolutionary asymmetric path-relinking (EvAPR).

INTEGRATED TERRESTRIAL-SATELLITE NETWORKS：PART ONE

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China Communications 2018年第8期15卷 I0004-I0006页

作者： linling kuang zhiyong feng yi qian giovanni giambene the tsinghua space center tsinghua university，China beijing university of posts and telecommunications (bupt)，China the key laboratory of universal wireless communications ministry of education the department of electrical and computer engineering university of nebraska-lincoln (unl) ieee vehicular technology society ieee

The rapid growing data traffic brings more and more pressure to the wireless networks,which is predicted to increase by over 10,000 times in the next 20 ***,currently,there is still large number of population without ... 详细信息

关键词：无线网络卫星陆上

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Multi-UAV Collaborative Edge Computing Algorithm for Joint Task Offloading and Channel Resource Allocation

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Journal of Communications and Information Networks 2024年第2期9卷 137-150页

作者： Yuting Wei Sheng Wu Zhe Ji Zhigang Yu Chunxiao Jiang linling kuang School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China China Academy of Electronics and Information Technology Beijing 100041China Beijing National Research Center for Information Science and Technology Tsinghua Space CenterTsinghua UniversityBeijing 100084China

Unmanned aerial vehicle (UAV)-based edge computing is an emerging technology that provides fast task processing for a wider area. To address the issues of limited computation resource of a single UAV and finite communication resource in multi-UAV networks, this paper joints consideration of task offloading and wireless channel allocation on a collaborative multi-UAV computing network, where a high altitude platform station (HAPS)is adopted as the relay device for communication between UAV clusters consisting of UAV cluster heads (ch-UAVs) and mission UAVs (m-UAVs). We propose an algorithm, jointing task offloading and wireless channel allocation to maximize the average service success rate (ASSR)of a period time. In particular,the simulated annealing(SA)algorithm with random perturbations is used for optimal channel allocation,aiming to reduce interference and minimize transmission delay.A multi-agent deep deterministic policy gradient (MADDPG) is proposed to get the best task offloading strategy. Simulation results demonstrate the effectiveness of the SA algorithm in channel allocation. Meanwhile,when jointly considering computation and channel resources,the proposed scheme effectively enhances the ASSR in comparison to other benchmark algorithms.

关键词： UAV-based edge computing multi-UAV collaboration joint task offloading and wireless channel allocation simulated annealing(SA)algorithm multi-agent deep deterministic policy gradient(MADDPG)

LEO constellation design methodology for observing multi-targets

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Astrodynamics 2018年第2期2卷 121-131页

作者： Chen Zhang Jin Jin linling kuang Jian Yan Tsinghua Space Center Tsinghua UniversityBeijingChina

This paper is based on the second problem of the 8th China Space Trajectory Design Competition(CTOC8).The background is LEO constellation design strategy for monitoring discrete multi-targets with small stellite under J *** difculty is that the small satellite is equipped with low-cost cameras with limited coverage ability and the targets are distributed separately in a key area,which result in long revisit time or large pumber of satelites based on traditional design *** this paper,a speciflc LEO consellation design method is proposed to cope with the ***,grid search and numerical method are performed to construct a database consisting of repeating ground track *** several orbits are carefully selected by pruning method to visit each ***,repeating ground track costellation is constructed to meet the maximun revisit time *** present method provides a systematic constellation design methodology of remote sensing observation with limited coverage ability,and demonstrates the resulting constellation can obtain rapid revisit frequency over discrete multi-targets with the least number of satellites.

关键词： satellite constellation remote sensing satellites repeating ground track orbit orbit perturbation pruning method

Analysis and Modeling of Traffic Characteristics for high-efficient scheduling in TDRSS

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Analysis and Modeling of Traffic Characteristics for high-ef...

2016年航空科学与技术全国博士生学术论坛

作者： Lei Wang Chunxiao Jiang linling kuang School of Aerospace Engineering Tsinghua University

To improve the scheduling efficiency of the tracking and data relay satellite system（TDRSS）, most previous work focused on the scheduling models and its algorithms, rather than the translation procedure from the requirements of customers to the input traffic data for scheduling. In this paper, we propose a complete traffic characteristics model that captures the requirements for TDRSS of diversified customers based on the empirical distribution of real traffic. Compared with previous traffic models of TDRSS that concentrated only in the time domain, the proposed model can depict the traffic characteristics in both time and space dimensions. Specifically, the proposed model consists of five main components which are integrated and implemented as the system traffic generator software, whereby multiple types of traffic with different distribution can be accurately generated. Numerical simulations are conducted in two scheduling scenarios which demonstrate the efficacy of the traffic characteristics model. This model can also be used in the computer simulation of the whole system performance as well as the optimization of inter-satellite routing algorithms.

关键词： space information network traffic characteristics model scheduling joint distribution of time and space

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基于时空特征的中继卫星系统业务模型

清华大学学报（自然科学版） 2017年第1期57卷 55-60,66页

作者：王磊匡麟玲黄惠明清华大学航天航空学院北京100084 北京空间信息中继传输技术研究中心北京100094 清华大学宇航技术研究中心北京100084

对中继卫星系统业务特征的分析和建模是系统资源调度优化问题的关键。基于系统调度原理和实际运控特点,构建了一个能够统一表征用户中继业务的参数化模型,可从时间、空间2个维度描述中继业务特征。通过引入中继卫星天线指向角度作为空... 详细信息

对中继卫星系统业务特征的分析和建模是系统资源调度优化问题的关键。基于系统调度原理和实际运控特点,构建了一个能够统一表征用户中继业务的参数化模型,可从时间、空间2个维度描述中继业务特征。通过引入中继卫星天线指向角度作为空间维度变量,改进传统的业务时序约束关系,解决了现有业务模型对时间和空间特征描述不准确的问题。对中继卫星系统业务数据进行分析和调度数值仿真,检验了模型的有效性。仿真结果表明:采用新的业务模型后,中继业务调度完成率平均增加10.65%,单址天线无效资源占比平均减少12.85%,有效提升了中继卫星系统效益。

关键词：中继卫星系统业务模型时空特征调度