检索结果-内蒙古大学图书馆

Energy-efficient buffer-aided relaying systems with opportunistic spectrum access

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Wang, Kunlun Wu, Qingqing Chen, Wen Yang, Yang Ng, Derrick Wing Kwan School of Information Science and Technology ShanghaiTech University Shanghai China Shanghai China Department of Electrical and Computer Engineering National University of Singapore Singapore Singapore Shanghai Institute of Advanced Communications and Data Sciences Department of Electronics Engineering Shanghai Jiao Tong University China School of Electrical Engineering and Telecommunications University of New South Wales SydneyNSW2052 Australia

In this paper, an energy-efficient cross-layer design framework is proposed for cooperative relaying networks, which takes into account the influence of spectrum utilization probability. Specifically, random arrival traffic is considered and an adaptive modulation and coding (AMC) scheme is adopted in the cooperative transmission system to improve the system performance. The average packet dropping rate of the relay-buffer is studied at first. With the packet dropping rate and stationary distribution of the system state, the closed-form expression of the delay is derived. Then the energy efficiency for relay-assisted transmission is investigated, which takes into account the queueing process of the relay and the source. In this context, an energy efficiency optimization problem is formulated to determine the optimum strategy of power and time allocation for the relay-assisted cooperative system. Finally, the energy efficient switching strategy between the relay assisted transmission and the direct transmission is obtained, where packet transmissions have different delay requirements. In addition, energy efficient transmission policy with AMC is obtained. Numerical results demonstrate the effectiveness of the proposed design improving the energy efficiency. Copyright © 2020, The Authors. All rights reserved.

关键词： Energy efficiency

MSTNN: A Graph Learning Based Method for the Origin-Destination Traffic Prediction

学校读者我要写书评

暂无评论

MSTNN: A Graph Learning Based Method for the Origin-Destinat...

IEEE International Conference on communications (ICC)

作者： Chenming Yang Zhiheng Zhou Hui Wen Liang Zhou National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of China Chengdu P. R. China Department of Computer Science and Engineering University of Electronic Science and Technology of China Chengdu P. R. China

ISBN: (数字)9781728150895

ISBN: (纸本)9781728150901

Accurate origin-destination traffic prediction (ODTP) is a persistent problem in network management. Due to the structural nature of networks, the spatial correlations are critical for effective perdition. In this paper, the ODTP problem is built onto the graph domain by mapping OD traffic into graph-structured data involving the topology information. Moreover, due to the flow characteristics of OD traffic, the complex spatial-temporal (ST) correlations should not be limited at one-hop neighbors or consecutive time steps. To benefit from this observation, we propose a novel graph learning based method, called multi-scale spatial-temporal graph neural network (MSTNN). In MSTNN, spatial and temporal extractors are designed to capture multi-scale spatial and temporal correlations. Specifically, the spatial extractor employs the graph attention mechanism to capture the time-varying spatial correlations of nodes and their multi-hop neighbors. In the temporal extractor, we design gated dilated convolution layers with different dilation factors, each of which represents a different granularity of time, to exploit the multi-scale temporal correlations in both adjacent and non-adjacent time steps. After cascading the spatial and temporal extractors, the multi-scale ST correlations are weighted fused. Simulations on two real-world datasets show that MSTNN outperforms existing approaches that work well in various prediction tasks.

关键词： Correlation Convolution Logic gates Feature extraction Learning systems Neural networks Task analysis

The Impact of Side Information on Physical Layer Security under Correlated Fading Channels

学校读者我要写书评

暂无评论

arXiv 2021年

作者： Ghadi, Farshad Rostami López-Martínez, F. Javier Zhu, Wei-Ping Gorce, Jean-Marie Universidad de Málaga Málaga29010 Spain The Dept. Signal Theory Networking and Communications University of Granada Granada18071 Spain Department of Electrical and Computer Engineering Concordia University MontrealQCH3G 1M8 Canada The Laboratoire CITI The Université de Lyon INRIA INSA de Lyon 6 Avenue des Arts VilleurbanneF-69621 France

In this paper, we investigate the impact of side information (SI) on the performance of physical layer security (PLS) under correlated fading channels. By considering non-causally known SI at the transmitter and exploiting the copula technique to describe the fading correlation, we derive closed-from expressions for the average secrecy capacity (ASC) and secrecy outage probability (SOP) under positive/negative dependence conditions. We indicate that considering such knowledge at the transmitter is beneficial for system performance and ensures reliable communication with higher rates, as it improves the SOP and brings higher values of the ASC. Copyright © 2021, The Authors. All rights reserved.

关键词： Transmitters

Coordination in Adversarial Multi-Agent with Deep Reinforcement Learning Under Partial Observability

学校读者我要写书评

暂无评论

Coordination in Adversarial Multi-Agent with Deep Reinforcem...

International Conference on Tools for Artificial Intelligence (ICTAI)

作者： Elhadji Amadou Oury Diallo Toshiharu Sugawara Department of Computer Science and Communications Engineering Waseda University 3-4-1 Okubo Shinjuku-ku Tokyo Japan

We propose a method using several variants of deep Q-network for learning strategic formations in large-scale adversarial multi-agent systems. The goal is to learn how to maximize the probability of acting jointly as coordinated as possible. Our method is called the centralized training and decentralized testing (CTDT) framework that is based on the POMDP during training and dec-POMDP during testing. During the training phase, the centralized neural network's inputs are the collections of local observations of agents of the same team. Although agents only know their action, the centralized network decides the joint action and subsequently distributes these actions to the individual agents. During the test, however, each agent uses a copy of the centralized network and independently decides its action based on its policy and local view. We show that deep reinforcement learning techniques using the CTDT framework can converge and generate several strategic group formations in large-scale multi-agent systems. We also compare the results using the CTDT with those derived from a centralized shared DQN and then we investigate the characteristics of the learned behaviors.

关键词：

Robust beamforming design for covert communications

学校读者我要写书评

暂无评论

arXiv 2021年

作者： Ma, Shuai Zhang, Yunqi Li, Hang Lu, Songtao Al-Dhahir, Naofal Zhang, Sha Li, Shiyin School of Information and Control Engineering China University of Mining and Technology Xuzhou221116 China National Mobile Communications Research Laboratory Southeast University Nanjing210096 China Shenzhen Research Institute of Big Data Shenzhen Guangdong518172 China IBM Thomas J. Watson Research Center Yorktown HeightsNY10598 United States Electrical and Computer Engineering Department University of Texas at Dallas DallasTX75080 United States Shenzhen Institute of Radio Testing and Tech Shenzhen518000 China

In this paper, we consider a common unicast beamforming network where Alice utilizes the communication to Carol as a cover and covertly transmits a message to Bob without being recognized by Willie. We investigate the beamformer design of Alice to maximize the covert rate to Bob when Alice has either perfect or imperfect knowledge about Willie’s channel state information (WCSI). For the perfect WCSI case, the problem is formulated under the perfect covert constraint, and we develop a covert beamformer by applying semidefinite relaxation and the bisection method. Then, to reduce the computational complexity, we further propose a zero-forcing beamformer design with a single iteration processing. For the case of the imperfect WCSI, the robust beamformer is developed based on a relaxation and restriction approach by utilizing the property of Kullback-Leibler divergence. Furthermore, we derive the optimal decision threshold of Willie, and analyze the false alarm and the missed detection probabilities in this case. Finally, the performance of the proposed beamformer designs is evaluated through numerical experiments. © 2021, CC BY.

关键词： Channel state information

Scoring the terabit/s goal: Broadband connectivity in 6G

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Rajatheva, Nandana Atzeni, Italo Bicaïs, Simon Björnson, Emil Bourdoux, André Buzzi, Stefano D'Andrea, Carmen Doré, Jean-Baptiste Erkucuk, Serhat Fuentes, Manuel Guan, Ke Hu, Yuzhou Huang, Xiaojing Hulkkonen, Jari Jornet, Josep Miquel Katz, Marcos Makki, Behrooz Nilsson, Rickard Panayirci, Erdal Rabie, Khaled Rajapaksha, Nuwanthika Salehi, Mohammadjavad Sarieddeen, Hadi Shahabuddin, Shahriar Svensson, Tommy Tervo, Oskari Tölli, Antti Wu, Qingqing Xu, Wen Centre for Wireless Communications University of Oulu Finland CEA-Leti France KTH Royal Institute of Technology Sweden Linköping University Sweden IMEC Belgium University of Cassino and Southern Latium Italy Italy Department of Electrical and Electronics Engineering Kadir Has University Turkey Fivecomm Valencia Spain State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University China The Beijing Engineering Research Center of High-Speed Railway Broadband Mobile Communications China Algorithm Department ZTE Corporation China School of Electrical and Data Engineering Faculty of Engineering and Information Technology University of Technology Sydney Australia Nokia Bell Labs Finland Institute for the Wireless Internet of Things Department of Electrical and Computer Engineering Northeastern University United States Ericsson Research Gothenburg Sweden Department of Computer Science Electrical and Space Engineering Luleå University of Technology Sweden Department of Engineering Manchester Metropolitan University United Kingdom Division of Computer Electrical and Mathematical Sciences and Engineering King Abdullah University of Science and Technology Saudi Arabia Nokia Finland Department of Electrical Engineering Chalmers University of Technology Sweden State Key Laboratory of Internet of Things for Smart City Department of Electrical and Computer Engineering University of Macau China Huawei Technologies Germany

This paper explores the road to vastly improving the broadband connectivity in future 6G wireless systems. Different categories of use cases are considered, with peak data rates up to 1 Tbps. Several categories of enablers at the infrastructure, spectrum, and protocol/algorithmic levels are required to realize the intended broadband connectivity goals in 6G. At the infrastructure level, we consider ultra-massive MIMO technology (possibly implemented using holographic radio), intelligent reflecting surfaces, user-centric cell-free networking, integrated access and backhaul, and integrated space and terrestrial networks. At the spectrum level, the network must seamlessly utilize sub-6 GHz bands for coverage and spatial multiplexing of many devices, while higher bands will be mainly used for pushing the peak rates of point-to-point links. Finally, at the protocol/algorithmic level, the enablers include improved coding, modulation, and waveforms to achieve lower latency, higher reliability, and reduced complexity. © 2020, CC BY.

关键词： MIMO systems

Reflections in the Sky: Millimeter Wave Communication with UAV-Carried Intelligent Reflectors

学校读者我要写书评

暂无评论

Reflections in the Sky: Millimeter Wave Communication with U...

IEEE Global communications Conference

作者： Qianqian Zhang Walid Saad Mehdi Bennis Bradley Department of Electrical and Computer Engineering Virginia Tech VA USA Center for Wireless Communications University of Oulu Finland

ISBN: (数字)9781728109626

ISBN: (纸本)9781728109633

In this paper, a novel approach that uses an unmanned aerial vehicle (UAV)-carried intelligent reflector (IR) is proposed to enhance the performance of millimeter wave (mmW) networks. In particular, the UAV-IR is used to intelligently reflect mmW beamforming signals from a base station towards a mobile outdoor user, while harvesting energy from mmW signals to power the IR. To maintain a line-of-sight (LOS) channel, a reinforcement learning (RL) approach, based on Q-learning and neural networks, is proposed to model the propagation environment, such that the location and reflection coefficient of the UAV-IR can be optimized to maximize the downlink transmission capacity. Simulation results show a significant advantage for using a UAV-IR over a static IR, in terms of the average data rate and the achievable downlink LOS probability. The results also show that the RL-based deployment of the UAV-IR further improves the network performance, relative to a scheme without learning.

关键词： Downlink Array signal processing Radio frequency Wireless communication Antennas Signal to noise ratio Coherence

A Privacy-Preserving Query System using Fully Homomorphic Encryption with Real-World Implementation for Medicine-Side Effect Search 2019

学校读者我要写书评

暂无评论

A Privacy-Preserving Query System using Fully Homomorphic En...

Proceedings of the 21st International Conference on Information Integration and Web-based Applications & Services

作者： Yusheng Jiang Tamotsu Noguchi Nobuyuki Kanno Yoshiko Yasumura Takuya Suzuki Yu Ishimaki Hayato Yamana Department of Computer Science and Communications Engineering Waseda University Shinjuku Tokyo Japan Bioinformatics Laboratory Department of Mathematical Sciences Meiji Pharmaceutical University Kiyose Tokyo Japan Regional Medicine Laboratory Department of Clinical Pharmacy Meiji Pharmaceutical University Kiyose Tokyo Japan Waseda University Shinjuku Tokyo Japan

ISBN: (纸本)9781450371797

The preservation of privacy during a search has become a serious problem in recent years. There is an increasing requirement to ensure that user queries are not abused by a third party, including the search provider. Fully homomorphic encryption (FHE) can conduct addition and multiplication directly over ciphertext. Using FHE, privacy, concerning both the user queries and the database of the search provider, can be protected. In this paper, we propose a privacy-preserving query system model. We implemented the proposed model in a real-world medicine side-effect query system. We applied a filtering technique, prior to the query deployment, to reduce the size of the database and used multi-threading to accelerate the search. The system was tested 10,000 times with a random query, using a database comprising 40,000 records of simulation data, and completed 99.84% of the queries within 60 seconds (s), proving the real-world applicability of our system.

关键词： privacy-preserving query system Fully homomorphic encryption medicine-side effect search

Miniaturized band pass filter using metamaterial half mode technique for substrate integrated waveguide

学校读者我要写书评

暂无评论

AIP Conference Proceedings 2023年第1期2977卷

作者： Mohammed Y. Yousif Faris Mohammed Ali Rand Muwafaq Hadi Communications Eng. Dept. Najaf Technical College Al-Furat Al-Al-Awsat Technical University Al-Najaf 31001 Iraq Najaf Technical Institute Al-Furat Al-Al-Awsat Technical University Al-Najaf 31001 Iraq Dentistry College University of Alkafeel Najaf Iraq Department of Computer Techniques Engineering College of Technical Engineering University of Alkafeel Najaf Iraq

In this paper, the half-mode evanescent substrate integrated waveguide SIW bandpass filter is proposed. The proposed filter operates under the cutoff frequency of the conventional SIW adopting the metamaterial technique. The operating frequency of the Full Mode Substrate Integrated Wave Guide FM-SIW is 2.2GHz, but the cutoff frequency of the conventional SIW structure is 5.2GHz. Fractal slots are cut out of the broad wall of the SIW. The first order bandpass filters are designed and simulated. The metamaterial technique led to miniaturization about 60 % from the conventional SIW structure. Also, the responses are compared to its counterpart which is the FM-SIW filter. No obvious difference is observed. Also, the Half Mode SIW technique was used for more miniaturization about 50% from the original structure of FM-SIW. Finally, the simulation results were highly accepted with the other works in literature.

关键词：