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IEEE Vehicular Technology Conference

作者： Zhaohui Yue Hui Gao Ruohan Cao Tiejun Lv Key Laboratory of Trustworthy Distributed Computing and Service Ministry of Education School of Information and Communication Engineering Beijing University of Posts and Telecommunications

ISBN: (纸本)9781479980895

This paper proposes a linear precoding that aims at maximizing the sum-rate in a multiuser multiple-input multiple-output (MU-MIMO) simultaneous wireless information and power transfer (SWIPT) system. In this scenario some receivers harvest energy while the others decode information at the same time. The sum-rate for information decoding users is considered as the optimization policy where the transmit power constraint and power harvesting per user constraints are taken into account. Since the objective function of the sum-rate maximization problem is non-convex, it is difficult to find the optimal solution. Thus, we propose an iterative algorithm to find a locally optimal design based on a sequential convex approximation (SCA) method. In this way, the non-convex optimization problem is approximated by a convex program at each iteration. Finally, with the aid of the concept of the Rate-Energy (R-E) region simulation results show that the proposed scheme achieves significant improvement compared to existing works.

关键词： Non-Convex prediction coding multiple input multiple output systems Transmitter power convex programming Optimal design DECODING Iterative algorithms Objective function Convexity

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Secure Beamforming Design in Wiretap MISO Interference Channels

Secure Beamforming Design in Wiretap MISO Interference Chann...

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IEEE Vehicular Technology Conference

作者： Jian Zhou Ruohan Cao Hui Gao Cong Zhang Tiejun Lv Key Laboratory of Trustworthy Distributed Computing and Service Ministry of Education School of Information and Communication Engineering Beijing University of Posts and Telecommunications

ISBN: (纸本)9781479980895

In this paper, we study the secrecy communication in two-user MISO interference networks where an external eavesdropper is interested in the messages transmitted by both transmitters. We propose a beamforming design to maximize the achievable secrecy sum rate of the transmitters subject to the individual power constraint at each transmitter. To transform this complex non-convex problem into a convex one, we propose an iterative algorithm based on the constrained concave convex procedure (CCCP) and successive convex approximation (SCA). It is observed that the proposed algorithm converges fast to a stationary point within a few iterations. Furthermore, we also propose a low-complexity null-space beamforming design scheme in which the beamforming vectors have closed-form solutions. Simulation results show the effectiveness of the two proposed schemes in improving the secrecy sum rate performance.

关键词： Array signal processing Interference Optimization Iterative methods Security Transmitting antennas

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Survey on the search of Internet of Things

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Tongxin Xuebao/Journal on Communications 2015年第12期36卷 57-76页

作者： Gao, Yun-Quan Li, Xiao-Yong Fang, Bin-Xing Key Laboratory of Trustworthy Distributed Computing and Service Ministry of Education Beijing University of Posts and Telecommunications Beijing100876 China School of Computer Science and Technology Anhui University of Technology Ma'anshan243032 China

With the popularization and development of the Internet of Things, the search of Internet of Things urgently needs to be solved in academia and industry and becomes a hot research topic. With the increasing data generated by sensors, only the search of IoT makes this data valuable. However, different from the traditional Internet search engines (such as Baidu, Google, Bing, Yahoo, etc), the search of IoT has different search objects and search architecture and data in the Internet of Things are massive, real-time, highly dynamic, heterogeneous, highly insecure. The above characteristics make search of IoT face more challenges. Firstly, the concept, characteristics, related technologies of search of IoT were summarized and presented. Secondly, several typical systems and related algorithms were described in detail. Finally, the current problems, the challenges and research prospects of this field for future were presented. © 2015, Editorial Board of Journal on Communications. All right reserved.

关键词： Surveys

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Analysis of the Performance of Hadoop Applications on Eucalyptus Cloud

Analysis of the Performance of Hadoop Applications on Eucaly...

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International Symposium on Security and Privacy in Social Networks and Big Data (SocialSec)

作者： Yiping Wang Xiaoyong Li Key Laboratory of Trustworthy Distributed Computing and Service (BUPT) Ministry of Education Beijing University of Posts and Telecommunications Beijing P.R. China

ISBN: (纸本)9781467384216

In cloud computing, enterprises and individual consumers can have access to storage, computing and bandwidth resources through network terminal, and do not need to install applications. Cloud computing can be divided into three categories: Software as a service (SaaS) and Platform as a service (PaaS) and Infrastructure as a service (IaaS). Eucalyptus is the most widely deployed IaaS cloud service software platform in the world. It builds a cloud service layer as IaaS by using the existing infrastructure. In this article, we built the Eucalyptus cloud platform on the server, and the deployment of software Dev C++ on the Eucalyptus platform. Consumers can have remote access to the software through the Internet without installing the software in the local. Over the last few years, Big Data analysis has attracted huge attention from enterprises and research institutions. Hadoop is considered as one of the most important tools in computing development in order to tackle the Big Data. It is very convenient for Eucalyptus to create and deploy the VM instances which is provided the distributed environment on demand, where the Hadoop applications are going to be executed. So we implement Hadoop platform on Eucalyptus cloud infrastructure, and evaluate the Hadoop applications running on Eucalyptus cloud under different stressing conditions.

关键词： Cloud computing Virtual machining Linux Computer architecture Big data

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A MOEA/D based approach for solving robust double row layout problem

A MOEA/D based approach for solving robust double row layout...

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Congress on Evolutionary Computation

作者： Lingling Tang Xingquan Zuo Chunlu Wang Xinchao Zhao Computer School Beijing University of Posts and Telecommunications Beijing China Key Laboratory of Trustworthy Distributed Computing and Service (BUPT) Ministry of Education Beijing China

ISBN: (纸本)9781479974931

In this paper, we propose a robust double row layout problem (RDRLP), where the material flow between any two machines may vary in different periods. A MOEA/D based solution approach is proposed to solve it. First, MOEA/D is used to find a collection of non-dominated machine sequences. Then, for each found machine sequence, MOEA/D is used to produce a set of non-dominated solutions. Finally, the final set of Pareto solutions is constructed from all the produced non-dominated solutions. The crowding-distance calculation is added to the procedure of updating the elite population to make nondominated solutions distributed uniformly. An integer coding and a real-valued coding with their corresponding crossover and mutation operators are presented. This approach is applied to a number of problem instances with 10-35 facilities and 3-5 periods. Experimental results show that the approach is able to effectively solve this problem.

关键词： Layout Encoding Robustness Production Sociology Statistics Optimization

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Novel Opportunistic Interference Mitigation Schemes for Heterogeneous Networks

Novel Opportunistic Interference Mitigation Schemes for Hete...

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IEEE Vehicular Technology Conference

作者： Deyue Zhang Hui Gao Yuan Ren Tiejun Lv Chau Yuen Key Lab of Trustworthy Distributed Computing and Service Ministry of Education Beijing University of Posts and Telecommunications Singapore University of Technology and Design

ISBN: (纸本)9781479980895

This paper considers to mitigate the uplink cross-tier interference (CI) in heterogeneous networks (HetNets) by the idea of opportunistic transmission. Firstly, we introduce the conventional opportunistic interference alignment (OIA) into HetNets and it indeed reduces the CI from the macrocell users (MUs) effectively. Interestingly, based on the unique characteristic in HetNets, the performance of OIA can be further improved. Therefore, the novel opportunistic interference mitigation (OIM) schemes based on adaptive reference signal spaces (A-RSSs) are proposed. In the novel OIM, an A-RSS is defined for each FBS and the A-RSS of a FBS constantly updates as the channel state information (CSI) of its FUs changes. According to the A-RSSs of all FBSs, each MU calculates its scheduling metric and the macrocell base station (MBS) selects MUs by the metrics. However, broadcasting the A-RSS constantly makes the system more complicated, so a complexity-performance tradeoff is considered. To decrease the complexity of the system, the quantization codebook is introduced and the quantized A-RSS based OIM is proposed. At last, extensive simulations are conducted. It is shown that, in terms of femtocells, the performance of novel OIM is better than that of the codebook based OIM (CB-OIM) and the performance of CB-OIM is better than that of conventional OIA.

关键词： Interference Femtocells Macrocell networks Measurement Computer integrated manufacturing Uplink Quantization (signal)

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Iterative grouping calibration for channel reciprocity in TDD MU-MIMO systems

Iterative grouping calibration for channel reciprocity in TD...

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International Conference on Communications and Networking in China (CHINACOM)

作者： Qiang Liu Xin Su Jie Zeng Tiejun Lv Hui Gao Key Laboratory of Trustworthy Distributed Computing and Service Beijing University of Posts and Telecommunications Beijing China Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing China

ISBN: (纸本)9781479987962

In this paper, we propose a new iterative grouping calibration algorithm for channel reciprocity in MU-MIMO (multiuser multiple-input multiple-output) systems. We assume the system operate in Time-division duplex (TDD). Because the TDD channel is reciprocal, we can use the uplink channel to estimate the downlink channel. The free-space electromagnetic channel can be regard as reciprocal channel in TDD channel. However, the generalized channel do not only consist of free-space electromagnetic channel, but also include transceiver circuitry. And in general case, the transceiver circuitry isn't perfect. For that reason, the reciprocity of generalized channel is destroyed. In this paper, we set a base station with one antenna to be the reference user, then we divide the MIMO BS antennas into N groups. We assume the users and every antenna group reform a new user-antenna group, the scope of transceiver circuitry coherence time in different user-antenna group are different. We only calibrate one user-antenna group in one free-space electromagnetic channel coherence time. The iterative grouping calibration algorithm in this paper can improve the channel capacity by transmitting pilot and signal at the same time slot. And the iterative grouping calibration algorithm goes especially well with massive mimo systems and high-speed mobile environment for its flexible antenna grouping.

关键词： Calibration Antennas Transceivers Coherence MIMO Downlink Electromagnetics

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An improved relative channel reciprocity calibration method in TDD massive MIMO systems

An improved relative channel reciprocity calibration method ...

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International Conference on Wireless and Optical Communications ( WOCC)

作者： Qiang Liu Xin Su Jie Zeng Hui Gao Tiejun Lv Xibin Xu Chiyang Xiao Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing China Key Laboratory of Trustworthy Distributed Computing and Service Beijing University of Posts and Telecommunications Beijing China

In this paper, we introduce an improved relative channel reciprocity calibration method in TDD massive multiple-input multiple-output (MIMO) systems. The improved calibration method divide the massive MIMO system into one Single-Input Single-Output (SISO) system and two Single-Input Multiple-Output (SIMO) systems instead of calibrating the massive MIMO directly. We select the channel with high channel gain to be the reference channel (the SISO system), the antennas of the SISO system are the reference antennas. At the same station the reference antenna and the other antennas consist the SIMO system. The three systems include all the receive circuitry and the transmit circuitry information of the massive MIMO system. We calibrate the three systems and acquire the calibration coefficients. Then we use the calibration coefficients of the three systems to calibrate the massive MIMO system. The proposed calibration method in this paper can reduce the amount of feedback and the computation complexity compared with calibrating the massive MIMO directly. What's more, the improved calibration method outperforms the traditional calibration method under high-speed mobile environment.

关键词： Calibration MIMO Downlink Uplink Radio transmitters Transmitting antennas

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service QoS Monitoring and Analyzing Based on Eucalyptus

Service QoS Monitoring and Analyzing Based on Eucalyptus

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International Conference on Computer Science and Network Technology

作者： Zefeng Gao Xiaoyong Li School of Computer Beijing University of Posts and Telecommunications Beijing China Key Laboratory of Trustworthy Distributed Computing and Service Ministry of Education Beijing University of Posts and Telecommunications Beijing China

ISBN: (纸本)9781467381741

The rapid development of the Internet provides a platform for the sharing of resource, and it has become a focus of the information society with user's increasing demand for network services year by year. With the development of cloud computing technology, it provides a solution for resource sharing. But due to uncertainty of cloud computing user requests, if there is not reasonable allocation and management of resources, it will lead to the uneven distribution of the resource, furthermore, the greater heterogeneity of the hardware will also lead to bottleneck or idle. How to achieve rational utilization of resources and provide reliable and transparent integration services for the user in the dynamic and open network environment is one of the main goals of cloud computing. This paper mainly discusses the cloud system monitoring and analysis. We use the parameter values of the node that are collected by monitoring system to get the QoS values, which are comprehensive values calculated from three aspect: basing on the node, cluster and dynamic parameters. And then we use the algorithm to calculate and analyse these data.

关键词： Component Cloud computing Eucalyptus Monitor QoS Cloud computing Eucalyptus wood Quality of service MONITOR information society system monitoring Resource utilization management of resources open network Resource sharing dynamic parameter

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Achieve High Availability about Point-Single Failures in OpenStack

Achieve High Availability about Point-Single Failures in Ope...

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International Conference on Computer Science and Network Technology

作者： Yiping Wang Xiaoyong Li Key Laboratory of Trustworthy Distributed Computing and Service (BUPT) Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 P.R. China. Beijing China

ISBN: (纸本)9781467381741

This paper describes a method to solve the complexity of distributed environment in cloud technology and the single-point failure problem. In this paper, we take the virtual machine failure and host failure in OpenStack into consideration. The ability of fast restoration of this service is achieved by components in OpenStack which is called ceilometer and new components named Senlin. The function is achieved by adding patches and modifying the source code in OpenStack. Ceilometer plays a role of collecting information of the virtual machine failure and host failure in OpenStack and transfers this information to Senlin. Then Senlin can make a decision to restore the failure. This clever method achieves the high availability of OpenStack. We implement the proposed method and show the effectiveness of fast restoration.

关键词： High Availability OpenStack IaaS ceilometer Senlin cloud Cellometers high availability CLOUDS Clouds

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