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GLOBECOM 2020 - 2020 IEEE Global Communications Conference

作者： Yujie Yang Yang Yang Congcong Wang Caili Guo Hailun Xia Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing China Beijing Laboratory of Advanced Information Networks School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing China

ISBN: (数字)9781728182988

ISBN: (纸本)9781728182995

This paper proposes a hybrid dimming scheme based on joint design of transmit antenna selection and precoding (TASP-HD) for dimmable multi-cell multi-user multiple-input single-output visible light communications systems. In TASPHD, both the direct current bias and the number of activated light-emitting-diodes are dynamically adjusted to achieve efficient communications under the constraints of dimming level and illumination uniformity. With the goal of maximizing the sum-rate of users, a joint transmit antenna selection and precoding design problem is formulated. This problem is a non-convex, mixed integer problem, and thus it is non-deterministic polynomial time hard. To solve the problem, the original problem is separated into two subproblems. The first subproblem is a mixed integer problem in terms of transmit antenna selection, which is solved by the branch-and-bound algorithm. With the obtained transmit antenna selection matrix, the second subproblem in terms of the precoding matrix is solved by the Lagrangian dual method. Finally, these two subproblems are iteratively solved to obtain a convergent solution. The simulation results verify that the proposed TASP-HD can achieve 6 dB signal-to-noise ratio gains over the analog dimming scheme when the dimming level is 70% for a target bit error rate of 10 -3 .

关键词： Light emitting diodes Precoding Lighting Transmitting antennas Optical transmitters Simulation Signal to noise ratio

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An Enhanced Camera Assisted Received Signal Strength Ratio Algorithm for Indoor Visible Light Positioning

An Enhanced Camera Assisted Received Signal Strength Ratio A...

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IEEE International Conference on Communications Workshops, ICC

作者： Lin Bai Yang Yang Chunyan Feng Caili Guo Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing China Beijing Laboratory of Advanced Information Networks School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing China

ISBN: (数字)9781728174402

ISBN: (纸本)9781728174419

In this paper, an enhanced camera assisted received signal strength ratio (eCA-RSSR) positioning algorithm is proposed for visible light positioning (VLP) systems. The basic idea of eCA-RSSR is to utilize visual information captured by the camera to estimate the incidence angles of visible lights first. Based on the incidence angles, eCA-RSSR utilizes the received signal strength ratios (RSSRs) calculated by the photodiode (PD) to estimate the ratios of the distances between the LEDs and the receiver. Based on the law of cosines, eCA-RSSR can transform the ratios of the distances into the absolute values. Then, the linear least square (LLS) method is employed to estimate the position of the receiver. Due to the combination of visual and strength information of visible light signals, eCA-RSSR has the following remarkable features: 1) eCA-RSSR only requires 3 LEDs for orientation-free 3D positioning, which achieves higher coverage than CA-RSSR, the RSSR and the perspective-n-point (PnP) algorithms; 2) eCA-RSSR can achieve higher accuracy than CA-RSSR, the RSSR and the PnP algorithms; 3) the complexity of eCA-RSSR is low due to the use of the LLS method. Simulation results show that the proposed approach can achieve centimeter-level accuracy over 80% indoor area regardless of the receiver orientations.

关键词： Light emitting diodes Cameras Optical transmitters Optical receivers Optical imaging Optical refraction

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Lightweight Task-Oriented Semantic Communication Empowered by Large-Scale AI Models

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IEEE Transactions on Vehicular Technology 2025年

作者： Liu, Chuanhong Guo, Caili Yang, Yang Chen, Mingzhe Quek, Tony Q. S. Beijing University of Posts and Telecommunications Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing100876 China Beijing University of Posts and Telecommunications Beijing Laboratory of Advanced Information Networks School of Information and Communication Engineering Beijing100876 China University of Miami Department of Electrical and Computer Engineering Institute for Data Science and Computing Coral GablesFL United States Singapore University of Technology and Design Dept. of Information Systems Technology and Design 487372 Singapore

Recent studies have focused on leveraging large-scale artificial intelligence (LAI) models to improve semantic representation and compression capabilities. However, the substantial computational demands of LAI models pose significant challenges for real-time communication scenarios. To address this, this paper proposes utilizing knowledge distillation (KD) techniques to extract and condense knowledge from LAI models, effectively reducing model complexity and computation latency. Nevertheless, the inherent complexity of LAI models leads to prolonged inference times during distillation, while their lack of channel awareness compromises the distillation performance. These limitations make standard KD methods unsuitable for task-oriented semantic communication scenarios. To address these issues, we propose a fast distillation method featuring a pre-stored compression mechanism that eliminates the need for repetitive inference, significantly improving efficiency. Furthermore, a channel adaptive module is incorporated to dynamically adjust the transmitted semantic information based on varying channel conditions, enhancing communication reliability and adaptability. In addition, an information bottleneck-based loss function is derived to guide the fast distillation process. Simulation results verify that the proposed scheme outperform baselines in term of task accuracy, model size, computation latency, and training data requirements. © 1967-2012 IEEE.

关键词： NP-hard

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Power Efficient LED Placement Algorithm for Indoor Visible Light Communication

arXiv

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arXiv 2020年

作者： Yang, Yang Zhiyu, Z.H.U. Caili, G.U.O. Feng, Chunyan Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing100876 China Beijing Laboratory of Advanced Information Networks School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing100876 China

This paper proposes a novel power-efficient light-emitting diode (LED) placement algorithm for indoor visible light communication (VLC). In the considered model, the LEDs can be designedly placed for high power efficiency while satisfying the indoor communication and illumination requirements. This design problem is formulated as a power minimization problem under both communication and illumination level constraints. Due to the interactions among LEDs and the illumination uniformity constraint, the formulated problem is complex and non-convex. To solve the problem, we first transform the complex uniformity constraint into a series of linear constraints. Then an iterative algorithm is proposed to decouple the interactions among LEDs and transforms the original problem into a series of convex sub-problems. Then, we use Lagrange dual method to solve the sub-problem and obtain a convergent solution of the original problem. Simulation results show that the proposed LED placement algorithm can harvest 22.86% power consumption gain when compared with the baseline scheme with centrally placed LEDs. Copyright © 2020, The Authors. All rights reserved.

关键词： Light emitting diodes

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SDN-based optimization model of virtual machine live migration over layer 2 networks 2nd

SDN-based optimization model of virtual machine live migrati...

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2nd International Conference on Computer, Communication and Computational Sciences, IC4S 2017

作者： Cui, Hongyan Zhang, Bo Chen, Yuyang Yu, Tao Xia, Zongguo Liu, Yunjie State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing100876 China Beijing Laboratory of Advanced Information Networks Beijing China Key Laboratory of Network System Architecture and Convergence Beijing China Institute of Network Science and Cyberspace Tsinghua University Tsinghua China School Official University of Massachusetts Boston Boston United States

ISBN: (纸本)9789811303432

Virtualization can provide significant benefits for service user by cutting the cost as well as enabling easy access. However, because the MAC table capacity of each host is limited, the traditional layer 2 networks have been unable to meet the needs of the numbers of virtual machines in the center. VXLAN has become an important layer 2 over layer 3 network transmission tunneling technology, a good solution to the data center internal virtual machine isolation and cross-data center transmission problems, but VXLAN does not propose a complete solution for virtual machine migration in the data center. Therefore, we design and implement the network model based on SDN, which optimizes the current VXLAN technology. This model separates the network plane from migration control plane, which can simplify the process of VXLAN and the complex network in data center. Moreover, we propose a detailed process for virtual machine migration supported by OpenFlow protocol. Some design in our model can really reduce the complexity of VXLAN technology and make it convenient for the users of virtual machine. © Springer Nature Singapore Pte Ltd. 2019.

关键词： Virtual machine

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Distributed reinforcement learning for age of information minimization in real-time IoT systems

arXiv

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arXiv 2021年

作者： Wang, Sihua Chen, Mingzhe Yang, Zhaohui Yin, Changchuan Saad, Walid Cui, Shuguang Poor, H. Vincent The Beijing Laboratory of Advanced Information Network The Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing100876 China The Department of Electrical and Computer Engineering Princeton University PrincetonNJ08544 United States The Department of Engineering King’s College London WC2R 2LS United Kingdom The Wireless@VT Bradley Department of Electrical and Computer Engineering Virginia Tech BlacksburgVA24060 United States Chinese University of Hong Kong Shenzhen518172 China

In this paper, the problem of minimizing the weighted sum of age of information (AoI) and total energy consumption of Internet of Things (IoT) devices is studied. In the considered model, each IoT device monitors a physical process that follows nonlinear dynamics. As the dynamics of the physical process vary over time, each device must find an optimal sampling frequency to sample the real-time dynamics of the physical system and send sampled information to a base station (BS). Due to limited wireless resources, the BS can only select a subset of devices to transmit their sampled information. Thus, edge devices must cooperatively sample their monitored dynamics based on the local observations and the BS must collect the sampled information from the devices immediately, hence avoiding the additional time and energy used for sampling and information transmission. To this end, it is necessary to jointly optimize the sampling policy of each device and the device selection scheme of the BS so as to accurately monitor the dynamics of the physical process using minimum energy. This problem is formulated as an optimization problem whose goal is to minimize the weighted sum of AoI cost and energy consumption. To solve this problem, we propose a novel distributed reinforcement learning (RL) approach for the sampling policy optimization. The proposed algorithm enables edge devices to cooperatively find the global optimal sampling policy using their own local observations. Given the sampling policy, the device selection scheme can be optimized thus minimizing the weighted sum of AoI and energy consumption of all devices. Simulations with real data of PM 2.5 pollution show that the proposed algorithm can reduce the sum of AoI by up to 17.8% and 33.9% and the total energy consumption by up to 13.2% and 35.1%, compared to a conventional deep Q network method and a uniform sampling policy. Copyright © 2021, The Authors. All rights reserved.

关键词： Energy utilization

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Deep Learning for Channel Decoding Under Correlated Noise

Deep Learning for Channel Decoding Under Correlated Noise

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作者： Xiangxiang Zhang Tao Luo Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications

Traditional Viterbi decoding algorithm degrades performance under correlated *** by the powerful learning from data of deep neural networks, we apply denoising convolutional neural network(DnCNN) to channel decoding under correlated *** this paper, we propose a DnCNN hard decision Viterbi decoder(short for DHDV decoder) architecture to enhance the performance of convolutional codes under correlated *** architecture applies DnCNN to denoise and improves the decoding SNR(signal to noise ratio) through the correlation of noise ***, the Viterbi Algorithm decoder decodes from the denoised *** decoder obtains greater BER performance improvement under stronger noise correlation, and it is robust under different convolutional codes and correlated noise *** the complexity of DnCNN network and matrix multiplication whitening method, DnCNN network complexity is lower when the code length is longer.

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A Metasurface Antenna with Dual Circularly Polarization for 5G Millimeter-Wave Applications

A Metasurface Antenna with Dual Circularly Polarization for ...

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IEEE International Conference on Electronic Information and Communication Technology (ICEICT)

作者： Junlong Chen Botao Feng Qingsheng Zeng Li Deng College of Electronics and Information Engineering Shenzhen University Shenzhen China Academy of Astronautics Nanjing University of Aeronautics and Astronautics Nanning China Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China

ISBN: (数字)9781728190457

ISBN: (纸本)9781728190464

A circularly polarized (CP) antenna based on metasurface with simple structure is proposed for 5G millimeter-wave (mmw) applications. This antenna mainly consists of three layers. Square patches with periodic rhombus grooves are placed on the top of the first layer. A pair of substrate integrated waveguide (SIW) feeding networks are orthogonally arranged in the second layer and third layer, respectively. Simulated experiments demonstrate that an overlapped frequency bandwidth of 5.4% (27.1-28.6 GHz) as well as a 3-dB axial ratio (AR) bandwidth of 7.9% (26.8-29 GHz) can be achieved in dual circularly polarized directions.

关键词： 5G mobile communication Millimeter wave technology Bandwidth Metasurfaces Millimeter wave communication Antennas Substrates

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A Wide-Beamwidth Magneto-Electric Dipole Antenna with Low Cross-Polarization and High Front-to-Back Ratio

A Wide-Beamwidth Magneto-Electric Dipole Antenna with Low Cr...

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IEEE International Conference on Electronic Information and Communication Technology (ICEICT)

作者： Liangying Li Wei Yan Botao Feng Li Deng College of Physics and Optoelectronic Engineering Shenzhen University Shenzhen China College of Electronics and Information Engineering Shenzhen University Shenzhen China Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China

ISBN: (数字)9781728190457

ISBN: (纸本)9781728190464

A novel magneto-electric (ME) dipole antenna is presented in this paper, which owns the characteristics of low cross polarization level and high front-to-back ratio (FBR) for the 5th-generation (5G) indoor communications is described. By dividing the conventional patches into two pairs of rectangle patches and four pieces of parasitic patches, the current which produces cross-polarization can be offset. Furthermore, the vertical fence can effectively widen the beamwidth of antenna. Experiment results demonstrate that a broad frequency bandwidth of 3.3-4.2 GHz (24%) can be achieved for 5G communications. Besides, a cross - polarization level below -20 dB and a FBR level of approximately 26 dB in the operating bands. Noting that a wide beamwidth of 100° for E-plane and H-plane is also obtained.

关键词： Indoor communication Dipole antennas 5G mobile communication Conferences Magnetoelectric effects Bandwidth Information and communication technology

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A Wideband Omni-directional Antenna Based on Printed Log-Periodic Element

A Wideband Omni-directional Antenna Based on Printed Log-Per...

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IEEE International Conference on Electronic Information and Communication Technology (ICEICT)

ISBN: (数字)9781728190457

ISBN: (纸本)9781728190464

In this paper, a novel omni-directional antenna with wideband and low cross-polarization for GSM1800/3G/LTE/5G indoor communication systems is proposed. By using the printed log-periodical antenna elements, which are evenly arranged around the center, the proposed antenna achieves the omnidirectional radiation patterns. Moreover, with the cooperation of the log-periodical antenna and the annular parasitic patches, a wide bandwidth and a good omnidirectional radiation performance are achieved simultaneously. Simulated results indicate that an impedance bandwidth of 1.7-3.8 GHz (76.4%) can be achieved with a gain of approximately 1.5 dBi across the whole operating frequency. Low cross-polarization level of less than -30 dB and compact size are also acquired.

关键词： Indoor communication Information and communication technology Broadband antennas Impedance Wideband Gain Antenna radiation patterns

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