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International Symposium on Antennas and Propagation (ISAP)

作者： Mengyu Wang Xing Xu Botao Feng Li Deng College of Optoelectronic Engineering Shenzhen University Shenzhen China College of Electronic Science and Technology Shenzhen University Shenzhen China Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Post and Telecommunications Beijing China

A graphene reflectarray is designed to realize two functions simultaneously at terahertz frequency: generating vortex waves, and steering the waves. Four parts of graphene patches with different values of reflection phase are used to generate vortex waves. On the other hand, generalized Snell's Law is applied to introduce additional reflection phase. Anomalous reflection is realized to steer the Vortex wave by 30 degrees.

关键词： Graphene Chemicals Surface waves Electric potential Telecommunications Plasmons

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An Error Compensation Method of Time Synchronization for Cross-domain Interconnection in SD-TSN

An Error Compensation Method of Time Synchronization for Cro...

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Optical Fiber Communication Conference, OFC 2016

作者： Zhang, Xiaodong Shou, Guochu Xue, Junli Li, Hongxing Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing100876 China

We propose a time synchronization modeling and error compensation method for Software-Defined TSN. Experiments verify that the combination method of POE and NNPID can effectively improve time synchronization performan...

ISBN: (纸本)9781943580071

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LBT with adaptive threshold for coexistence of cellular and WLAN in unlicensed spectrum 8

LBT with adaptive threshold for coexistence of cellular and ...

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8th International Conference on Wireless Communications and Signal Processing, WCSP 2016

作者： Li, Bin Zhang, Tiankui Zeng, Zhimin Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing100876 China

ISBN: (纸本)9781509028603

Coexistence of cellular networks and wireless local area network (WLAN) in unlicensed spectrum will be a vital application scenario in the future 5G network. Listen-before-talk (LBT) is one of the mechanisms to ensure a fair coexistence among various radio access networks. In this paper, we present a LBT algorithm with an adaptive threshold jointly considering the diverse traffic load conditions of cellular networks and the quality of service (QoS) metrics of user equipment (UE). The transmission procedure of a cellular base station (BS) is modeled utilizing M/GI/1 queuing system via queuing theory. Then the BS control the clear channel assessment (CCA) threshold according to the queue length to adapt to the diverse traffic loads under the condition of QoS guarantee. Simulation results show that the proposed algorithm achieves significant performance gain of the cellular network under the coexistence scenario on the premise of tolerable sacrifices on WLAN performance. © 2016 IEEE.

关键词： Wireless local area networks (WLAN)

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A QoS-based multi-rate multicast scheme over heterogeneous cellular network 13

A QoS-based multi-rate multicast scheme over heterogeneous c...

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13th International Symposium on Wireless Communication systems, ISWCS 2016

作者： Liu, Tang Xia, Hailun Chunyan, Feng Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing100876 China

ISBN: (纸本)9781509020614

Wireless multimedia traffic has increased considerably in recent years, which puts forward higher demand on the capacity of existing network. Multicast, as a transmission strategy with high spectral efficiency, has not been widely studied in heterogeneous cellular network (HetNet). In this paper, we propose a QoS-based multi-rate multicast scheme over HetNet to effectively improve the system throughput while guaranteeing the quality of service (QoS) of the whole system. We formulate an expression of system throughput of the proposed multicast scheme and decouple it into three subproblems for its computational complexity, namely, user association (UA), subgroup formation (SF) and resource allocation (RA). In UA, we present a traffic-oriented access method based on reference signal receiving power (RSRP). In SF, the associated users are divided into several subgroups according to their channel state information (CSI) and the users in one subgroup are served with the same rate determinated by the CSI level of the subgroup. In RA, fractional frequency reuse (FFR) mechanism is used to eliminate the co-channel cross-tier interference between macro base station (MBS) and small base stations (SBS). And QoS is considered both in subcarrier allocation and power allocation processes. Simulation results show that the system throughput is significantly improved while QoS is guaranteed by using our scheme. © 2016 IEEE.

关键词： Quality of service

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Diffraction Loss of Mobile Communications Electromagnetic Wave in L-corridor

Diffraction Loss of Mobile Communications Electromagnetic Wa...

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The 5th International Symposium on Electromagnetic Compatibility

作者： ZHOU Feng MA Zhen ZHANG Hai-man GAO Feng YUAN Xiu-hua ZHANG Xiang-yang China Academy of Information and Communication Technology China Mobile Communications Group Shan-xi Co.Ltd.Network Optimization Center School of Electronic Engineering Beijing University of Posts and Telecommunication Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunication

Diffraction loss exists in the corner of L-corridor in *** measurement and simulation show that conventional diffraction propagation model does not fit *** diffraction loss increases linearly with frequency on 0.831 G... 详细信息

关键词： L-corridor diffraction loss mobile communication

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An effective visual saliency detection method based on maximum entropy random walk

An effective visual saliency detection method based on maxim...

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2016 IEEE International Conference on Multimedia and Expo Workshop, ICMEW 2016

作者： Lu, Jingyu Wen, Xiangming Hua, Shao Lu, Zhaoming Chen, Yawen Beijing Laboratory of Advanced Information Networks Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications 100876 China

ISBN: (纸本)9781509015528

Visual saliency detection (VSD) has been attracting increasing attention due to its wide applications in computer visions. In this paper, a visual saliency detection method based on maximum entropy random walk (MEVSD) is proposed. Gaze wandering over images is modeled as a random walk process on a graph, in which the super-pixels and their similarities are regarded as nodes and edges respectively. The visual salient region is detected based on the stationary distribution of the stochastic process. Compared with the stat-of-the-art methods, MEVSD focuses on globally maximizing the entropy of walking trajectories. A two-tier neighbor scheme of super-pixels is proposed to reduce the computational complexity. Besides, a belief diffusion algorithm on weight matrix is proposed to improve precision rate. Extensive experiments with diverse content of pictures indicate that MEVSD performs well compared with 11 state-of-the-art methods. © 2016 IEEE.

关键词： Random processes

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Echo State Transfer Learning for Data Correlation Aware Resource Allocation in Wireless Virtual Reality

Echo State Transfer Learning for Data Correlation Aware Reso...

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Asilomar Conference on Signals, systems, and Computers

作者： Mingzhe Chen Walid Saad Changchuan Yin Merouane Debbah Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China Wireless@VT Virginia Tech Blacksburg VA USA Huawei France R&D Mathematical and Algorithmic Sciences Lab Paris France

In this paper, the problem of data correlation-aware resource management is studied for a network of wireless virtual reality (VR) users communicating over cloud-based small cell networks (SCNs). In the studied model, small base stations (SBSs) with limited computational resources act as VR control centers that collect the tracking information from VR users over the cellular uplink and send them to the VR users over the downlink. In such a setting, VR users may send or request correlated or similar data (panoramic images and tracking data). This potential spatial data correlation can be factored into the resource allocation problem to reduce the traffic load in both uplink and downlink. This VR resource allocation problem is formulated as a noncooperative game that allows jointly optimizing the computational and spectrum resources, while being cognizant of the data correlation. To solve this game, a transfer learning algorithm based on the machine learning framework of echo state networks (ESNs) is proposed. Unlike conventional reinforcement learning algorithms that must be executed each time the environment changes, the proposed algorithm can intelligently transfer information on the learned utility, across time, to rapidly adapt to environmental dynamics due to factors such as changes in the users' content or data correlation. Simulation results show that the proposed algorithm achieves up to 16.7% and 18.2% gains in terms of delay compared to the Q-learning with data correlation and Q-learning without data correlation. The results also show that the proposed algorithm has a faster convergence time than Q-learning and can guarantee low delays.

关键词： Correlation Uplink Delays Wireless communication Downlink Resource management Games

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An autonomous system collaboration caching strategy based on content popularity in CCN 27

An autonomous system collaboration caching strategy based on...

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27th IEEE Annual International Symposium on Personal, Indoor, and Mobile Radio Communications, PIMRC 2016

作者： Kaili, Wang Muqing, Wu Min, Zhao Yanqing, Cheng Beijing Key Laboratory of Network System Architechture and Convergence Beijing University of Posts and Telecommunications Beijing100876 China

ISBN: (纸本)9781509032549

The Content-Centric network (CCN) is a very important structure in the future network, in which every node has caching ability. Caching strategy has a decisive influence on the performance of the CCN. In this paper, an Autonomous system Collaboration Caching Strategy (ASCCS) is proposed to achieve the explicit collaboration, reduce the cache redundancy, improve the cache utilization rate and increase the cache hit rate. Firstly, the network is divided into several Autonomous systems (AS) before carrying out the centralized control. Then we select the control nodes according to the betweenness and the cache replacement rate of the nodes. Each AS is centralized controlled by the control node. At the same time, the selected control node computes the popularity statistics of different contents to determine the suitable cache policy for them. Under this strategy, nodes in the same AS cooperate with each other, which improves the transparency of the network cache, and thereby achieve the cache performance gain of the CCN. It makes the optimal performance of the cache become possible. © 2016 IEEE.

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A tri-band bandpass filter with wide stop band based on quad-mode stub loaded resonator

A tri-band bandpass filter with wide stop band based on quad...

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IEEE International Symposium on Electromagnetic Compatibility (EMC-beijing)

作者： Zhentao Zhao Shufang Li Jianfeng Zhu Meijun Qu Yang Kang Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing People's Republic of China Police Key Laboratory of IoT Application of the Ministry of Public Security of P.R.C First Research Institute of the Ministry of Public Security of PRC Beijing People's Republic of China

This paper presents a tri-band bandpass filter with high design flexibility in symmetrical structure and a wide stopband by using quad-mode stub loaded resonator. Stub-to-stub coupling is introduced to split two identical modes and produce two transmission zeros. The harmonic passband can be typically eliminated by regularly embedding open-circuited stubs in the feeding structure without affecting the performance of the three passbands. A filter prototype is simulated to validate the proposed design. The results show a desired wide upper stopband at 8.8 GHz with rejection better than 20 dB and three passbands are centered at 2.45 GHz, 3.68 GHz, and 5.19 GHz respectively, which is applicable to WLAN and WiMAX applications.

关键词： Band-pass filters Resonant frequency Passband Resonator filters Harmonic analysis Power harmonic filters Couplings

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Modelling and Forecasting of Commodity Trading Price

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Journal of Physics: Conference Series 2018年第1期1060卷

作者： Jun Liu Yuan Tian Qing Yan Center for Data Science BUPT Beijing 100876 China. School of Information and Communication Engineering BUPT Beijing 100876 China. Beijing Laboratory of Advanced Information Networks BUPT Beijing 100876 China. Beijing Key Laboratory of Network System Architecture and Convergence BUPT Beijing 100876 China.

This paper proposes and improves a model for China's cotton reserves trading market, generates a more accurate price level table in contrast to the widely used China Cotton Association(CCA)'s table, and predicts the future trading price with this model. Data used is all 29895 trade records of cotton reserves from May, 2016 to Sept, 2016. In this paper, we firstly give a briefly introduction to the data as well as basic knowledge of cotton, especially the CCA's price level table as the target to improve accuracy. We then present a multiple linear regression with dummy variable model, which can reduce the error on predicting the trading price of current month, but still remains some problems such as the result shows a batch of cotton with better quality may get a lower price. So we finally advance the model with multidimensional isotonic regression and more factors taken into consideration. Our last model could be used to predict the trade price of both current month and next month with approximately 4% mean absolute percentage error(MAPE).

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