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China Communications 2024年第2期21卷 227-244页

作者： Meng Meng Bo Hu Shanzhi Chen Jianyin Zhang State Key lab.of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China State Key lab.of Wireless Mobile Communication China Academy of Telecommunication TechnologyBeijing 100191China Research Institute of China Mobile Beijing 100053China

Lower Earth Orbit(LEO) satellite becomes an important part of complementing terrestrial communication due to its lower orbital altitude and smaller propagation delay than Geostationary satellite. However, the LEO satellite communication system cannot meet the requirements of users when the satellite-terrestrial link is blocked by obstacles. To solve this problem, we introduce Intelligent reflect surface(IRS) for improving the achievable rate of terrestrial users in LEO satellite communication. We investigated joint IRS scheduling, user scheduling, power and bandwidth allocation(JIRPB) optimization algorithm for improving LEO satellite system *** optimization problem of joint user scheduling and resource allocation is formulated as a non-convex optimization problem. To cope with this problem, the nonconvex optimization problem is divided into resource allocation optimization sub-problem and scheduling optimization sub-problem firstly. Second, we optimize the resource allocation sub-problem via alternating direction multiplier method(ADMM) and scheduling sub-problem via Lagrangian dual method ***, we prove that the proposed resource allocation algorithm based ADMM approaches sublinear convergence theoretically. Finally, we demonstrate that the proposed JIRPB optimization algorithm improves the LEO satellite communication system throughput.

关键词： convex optimization intelligent reflecting surface LEO satellite communication OFDM

Chip design of a 5.8-GHz fractional-N frequency synthesizer with a tunable G_m-C loop filter

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Chinese Physics B 2012年第8期21卷 270-277页

作者：黄进芳刘荣宜赖文政石钧纬许剑铭 Department of Electronic Engineering National Taiwan University of Science and Technology chunghwa telecommunication lab.ratory Chunghwa Telecom.Co.

This paper proposes a novel Gm-C loop filter instead of a conventional passive loop filter used in a phase-locked loop. The innovative advantage of the proposed architecture is tunable loop filter bandwidth and hence the process variations of passive elements of resistance R and capacitance C can be overcome and the chip area is greatly reduced. Furthermore, the MASH 1-1-1 sigma-delta （ZA） modulator is adopted for performing the fractional division number and hence improves the phase noise as well. Measured results show that the locked phase noise is -114.1 dBc/Hz with lower Gm-C bandwidth and -111.7 dBm/C with higher Gm-C bandwidth at 1 MHz offset from carrier of 5.68 GHz. Including pads and built-in Gm-C filter, the chip area of the proposed frequency synthesizer is 1.06 mm2. The output power is -8.69 dBm at 5.68 CHz and consumes 56 mW with an off-chip buffer from 1.8-V supply voltage.

关键词： Gm-C loop filter phase-locked loop PLL voltage-controlled oscillator (VCO)

Monitoring of PON System Using Compound Surveillance Technique

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Journal of Electronic Science and Technology 2015年第2期13卷 169-173页

作者： Sun-Chien Ko Hsiu-Jung Chuang Si-Chong Chen Chih-Yih Wang Sheng-Fwu Lin telecommunication lab.ratories Chunghwa Telecom Co.Ltd.

A passive optical network（PON） monitoring system combined light pulse and frequency sweep techniques is proposed and verified in a field test. The light pulse surveys over the all whole network and the frequency sweep are used to investigate any fault in the link. The field test is performed with 4 PONs. Each PON is monitored at 4 ports, one is the splitter port and the other three are arbitrary chosen multiple optical units（ONUs）. All the tested PONs are monitored in turns once per hour. Faults at the feeder and branch fiber have been observed in this field test and have been analyzed with the monitoring system.

关键词： verified arbitrary monitored splitter branch chosen reflective turns restoration realistic

A General Description Schema of Services for WSNs

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Chinese Journal of Electronics 2014年第3期23卷 604-610页

作者： SUN Yan MA Xiaoqiong LUO Hong Beijing Key lab.of Intelligent telecommunication Software and Multimedia Beijing University of Posts and Telecommunication

With the rapid development of Wireless sensor networks(WSNs) in recent years, users have been more interested in the services that WSNs can provide rather than data itself. To better bridge between data in different WSNs provided by different developers and comprehensive services required by users, a general service description language used in WSNs is needed. In this paper, we propose a general description schema of services— General service description language(GSDL), which is an XML-like language and can describe simple or composite services. This language makes use of tags agreement,compression and binary coding mechanisms so as to greatly reduce the size of service description document. Moreover,we design a lightweight service composition and decomposition algorithm, which can be executed at each service broker. Compared with widely used WSDL, GSDL is more compact, flexible and suitable for service description in WSNs.

关键词： Wireless sensor network General services description language Service composition Service decomposition

Impact of the second order dispersion on compensation of SPM in an adaptive pulse pre-shaping quasi-CPA system

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Optoelectronics Letters 2010年第1期6卷 41-44页

作者：耿蕊简水生 Key lab. of All Optical Network and Advanced telecommunication Network of Education Ministry of China and Instituteof Lightwave TechnologyBeijing Jiaotong University

A model of quasi-CPA (chirped pulse amplification) system, in which the input is the transform-limited Gaussian pulses, is set up numerically to investigate the impact of the second order dispersion on the adaptive compensation of self-phase modulation (SPM) effect. The adaptive phase pre-shaping controlled by differential evolution algorithm is introduced to the input pulse before amplification and recompression. With maximizing the peak power of the output pulse, the simulation results show that the normal dispersion is really helpful to eliminate the side lobes of the output pulse and increase the pulse peak power.

关键词：自适应补偿注册会计师脉冲整形二阶色散 SPM 啁啾脉冲放大差分进化算法峰值功率

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Tsinghua Science and Technology 2017年第2期22卷 174-184页

作者： Peng Li Hong Luo Yan Sun School of Computer Science Beijing University of Posts and TelecommunicationBeijing 100876China the Beijing Key lab.of Intelligent telecommunication Software and Multimedia Beijing 100876China

In this paper, we target a similarity search among data supply chains, which plays an essential role in optimizing the supply chain and extending its value. This problem is very challenging for application-oriented data supply chains because the high complexity of the data supply chain makes the computation of similarity extremely complex and inefficient. In this paper, we propose a feature space representation model based on key points,which can extract the key features from the subsequences of the original data supply chain and simplify it into a feature vector form. Then, we formulate the similarity computation of the subsequences based on the multiscale features. Further, we propose an improved hierarchical clustering algorithm for a similarity search over the data supply chains. The main idea is to separate the subsequences into disjoint groups such that each group meets one specific clustering criteria; thus, the cluster containing the query object is the similarity search result. The experimental results show that the proposed approach is both effective and efficient for data supply chain retrieval.

关键词： data supply chain similarity search feature space hierarchical clustering

Dynamic Loading Vulnerability Detection for Android Applications Through Ensemble Learning

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Chinese Journal of Electronics 2017年第5期26卷 960-965页

作者： YANG Tianchang CUI Haoliang NIU Shaozhang Beijing Key lab.of Intelligent telecommunication Software and Multimedia Beijing University of Posts and Telecommunications

Valid authentication and security protection measures are not provided for external code and resources executed by dynamic loading technology during the runtime in *** this paper,a new method of detecting vulnerabilities related to dynamic loading technology is *** phases are included in the detection *** analysis phase determines the location information of the loading point and extracts the feature vector for each loading *** phase classifies the extracted feature vector by means of constructed multilab.l classification ensemble learning *** to the examination result on 4464 Android applications,37.8% of all applications use the dynamic loading technology,and more than 12% of total test applications are detected with related security *** result shows that the detection method can detect vulnerabilities of dynamic loading effectively and is more comprehensive.

关键词： Dynamic loading Android application Vulnerability Ensemble learning

A CSI Acquisition Approach for mm Wave Massive MIMO

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China Communications 2019年第9期16卷 1-14页

作者： Shanzhi Chen Qiubin Gao Runhua Chen Hui Li Shaohui Sun Zhengxuan Liu State Key lab.of Wireless Mobile Communication China Academy of Telecommunication Technology

Massive Multiple-Input Multiple-Output(MIMO)is considered as a key technology for 4G and 5G wireless communication systems to improve spectrum efficiency by supporting large number of concurrent *** addition,for the target frequency band of 5G system,mmWave band,massive MIMO is pivotal in compensating the high *** this paper,we investigate the channel state information(CSI)acquisition problem for mmWave massive *** hybrid analog-digital antenna architecture,how to derive the analog beamforming and digital beamforming is *** iterative analog beam acquisition approach is proposed to save system overhead and reduce beam searching *** the digital beamforming,a grouping based codebook is proposed to facilitate CSI *** codebook is then extended to incorporate also analog beam ***,channel reciprocity is exploited to save CSI reporting overhead and a two-stage approach is proposed to fully utilize the channel reciprocity at both mobile station and base station side and accelerate the CSI acquisition procedure.

关键词： codebook CSI acquisition hybridbeamforming

Trusted Data Acquisition Mechanism for Cloud Resource Scheduling Based on Distributed Agents

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China Communications 2011年第6期8卷 108-116页

作者：李小勇杨月华 Beijing Key lab.of Intelligent telecommunication Software and Multimedia Beijing University of Posts and Telecommunications

Goud computing is a new paradigm in which dynamic and virtualized computing resources are provided as services over the Internet. However, because cloud resource is open and dynamically configured, resource allocation and scheduling are extremely important challenges in cloud infrastructure. Based on distributed agents, this paper presents trusted data acquisition mechanism for efficient scheduling cloud resources to satisfy various user requests. Our mechanism defines, collects and analyzes multiple key trust targets of cloud service resources based on historical information of servers in a cloud data center. As a result, using our trust computing mechanism, cloud providers can utilize their resources efficiently and also provide highly trusted resources and services to many users.

关键词： cloud computing trusted computing distributed agent resource scheduling

Crowd Density Field Estimation Based on Crowd Dynamics Theory and Social Force Model

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Chinese Journal of Electronics 2019年第3期28卷 521-528页

作者： WEI Xinlei DU Junping LIANG Meiyu XUE Zhe Beijing Key lab.of Intelligent telecommunication Software and Multimedia School of Computer ScienceBeijing University of Posts and Telecommunications

The local crowd density and the crowd distribution estimation tasks are useful but *** are two main problems which limit the performance of existing algorithms. The first one is that there are not enough lab.led training samples to build the highperformance estimation model. Another one is that existing methods lack the supports of physical theories of the crowd. To remedy them, a novel crowd density field model is proposed, which is deduced by jointing crowd dynamics theory and social force model. A crowd counting method based on the proposed crowd density field model is introduced to measure the proposed crowd density field model. Extensive experiments confirm the effectiveness of the proposed plan.

关键词： Social force model Crowd dynamics Crowd density field Computer vision