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arXiv 2018年

作者： Wang, Jun-Bo Cheng, Ming Wang, Jin-Yuan Lin, Min Wu, Yongpeng Zhu, Huiling Wang, Jiangzhou National Mobile Communications Research Laboratory Southeast University Nanjing210096 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing210003 China Shanghai Key Laboratory of Navigation and Location Based Services Shanghai Jiao Tong University Minhang200240 China School of Engineering and Digital Arts University of Kent Canterbury KentCT2 7NT United Kingdom

High-speed trains (HSTs) are being widely deployed around the world. To meet the high-rate data transmission requirements on HSTs, millimeter wave (mmWave) HST communications have drawn increasingly attentions. To realize sufficient link margin, mmWave HST systems employ directional beamforming with large antenna arrays, which results in that the channel estimation is rather time-consuming. In HST scenarios, channel conditions vary quickly and channel estimations should be performed frequently. Since the period of each transmission time interval (TTI) is too short to allocate enough time for accurate channel estimation, the key challenge is how to design an efficient beam searching scheme to leave more time for data transmission. Motivated by the successful applications of machine learning, this paper tries to exploit the similarities between current and historical wireless propagation environments. Using the knowledge of reinforcement learning, the beam searching problem of mmWave HST communications is formulated as a multi-armed bandit (MAB) problem and a bandit inspired beam searching scheme is proposed to reduce the number of measurements as many as possible. Unlike the popular deep learning methods, the proposed scheme does not need to collect and store a massive amount of training data in advance, which can save a huge amount of resources such as storage space, computing time, and power energy. Moreover, the performance of the proposed scheme is analyzed in terms of regret. The regret analysis indicates that the proposed schemes can approach the theoretical limit very quickly, which is further verified by simulation results. Copyright © 2018, The Authors. All rights reserved.

关键词： Millimeter waves

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A TDMA Based Cooperative Communication MAC Protocol for Vehicular Ad Hoc networks

A TDMA Based Cooperative Communication MAC Protocol for Vehi...

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IEEE Vehicular technology Conference

作者： Tianjiao Zhang Qi Zhu Jiangsu Key Lab of Wireless Communications Key Lab on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education Nanjing University of Posts and Telecommunications

ISBN: (纸本)9781509016990

In a VANET (Vehicular Ad Hoc network), the collisions caused by vehicles' mobility lead to poor network performance, especially in high-density network. In order to increase the flexibility of communication, this paper presents a communication protocol with dynamic choosing relay node and automatic cooperative communication called VC-TDMA (Vehicular Cooperative TDMA). The nodes can choose the multi-hop relay nodes rationally and other idle nodes can provide cooperative communication automatically. Considering batch arrival data traffic, the buffer queue state of nodes in the network is numerical analyzed by Markov Chain. The simulation results show that VC-TDMA can improve the throughput of the network compared with the conventional TDMA protocol.

关键词： VANETs Markov Chain Cooperative Communication TDMA time division multiple access Markov chain cooperative communication V2V Communication protocols Ganglia Trunk Node network node Simulation results

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Optimal power allocation based on sum-throughput maximization for energy harvesting cognitive radio networks

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IOP Conference Series: Earth and Environmental Science 2017年第1期52卷

作者： Zhenwei Xie Qi Zhu The Key Wireless Laboratory of Jiangsu Province Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Laboratory on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education Jiangsu Nanjing 210003 China

In this study, an optimal power allocation algorithm by maximizing the sum-throughput in energy harvesting cognitive radio networks is proposed. Under the causality constraints of the harvested energy by solar radiation, electromagnetic waves and so on in the two secondary users (SUs), and the interference constraint in the primary user (PU), the sum-throughput maximization problem is formulated. The algorithm decomposes the interference threshold constraint to the power upper bounds of the two SUs. Then, the power allocation problems of the two SUs can be solved by a directional water-filling algorithm (DWA) with the power upper bounds, respectively. The paper gives the algorithm steps and simulation results, and the simulation results verify that the proposed algorithm has obvious advantages over the other two algorithms.

关键词：

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Power allocation and relay selection scheme based on system outage probability for energy-harvesting cooperative network

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Journal of communications 2016年第10期11卷 903-909页

作者： Hao, Wang Qi, Zhu The Key Wireless Laboratory of Jiangsu Province School of Telecommunication and Information Engineering Nanjing University of Posts and Telecommunications Nanjing210003 China Key Laboratory on Wideband Wireless Communications Sensor Network Technology of Ministry of Education Nanjing210003 China

A power allocation and single relay selection scheme is proposed to improve the outage performance for a wireless cooperative network with multiple energy-harvesting relay nodes. The optimization problem is formulated to minimize the system outage probability under the constraints of both relay joint maximum transmit power and individual energy limitation caused by energy-harvesting. By using Lagrange multiplier method and KKT (Karush-Kuhn-Tucker) conditions, the optimal transmit power of multi-relay can be solved. Taking into consideration that single relay is more feasible to implement in practical communication scenarios, a best relay can be selected by calculating the contribution factor of relay nodes. In addition, the lower bound of system outage probability is derived in this paper. Simulation results show that the proposed power allocation and single relay selection scheme can reduce system outage probability efficiently, and verify the conclusion of the lower bound of outage probability. © 2016 Journal of communications.

关键词： Cooperative communication

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A QoS-based channel allocation and power control algorithm for device-to-device communication underlaying cellular networks

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Journal of communications 2016年第7期11卷 624-631页

作者： Yu, Bao-Zhou Qi, Zhu The Key Wireless Laboratory of Jiangsu Province School of Telecommunication and Information Engineering Nanjing University of Posts and Telecommunications Nanjing210003 China Key Laboratory on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education NanjingJiangsu210003 China

In device-to-device (D2D) communication system, rational resource allocation can effectively reduce the interference between cellular users and D2D users. In this paper, based on the QoS requirement of cellular users and D2D users, we propose a channel allocation and power control optimization algorithm, which takes limit transmission power of each cellular user and total D2D users into consideration when maximizing the system capacity of total D2D users. We can achieve the candidate cellular users set of D2D users according to the minimum SINR requirement of D2D users. And then, the transmission power of cellular users and D2D users are optimized with Lagrange multiplier method, meanwhile we calculate the capacity of each D2D user by optimal power and allocate channel to the D2D pair, which has the maximum value of capacity. However, the optimal algorithm has a high complexity. We further propose a low complexity suboptimal algorithm, which allocates channel and controls power in different stages. Simulation results show that the proposed algorithms effectively improve the capacity of D2D users under the condition of guaranteeing the QoS of cellular users and the suboptimal algorithm greatly reduces the complexity compared with the optimal algorithm. © 2016 Journal of communications.

关键词： Resource allocation

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A Normalization Model for Analyzing Multi-Tier Millimeter Wave Cellular networks

arXiv

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arXiv 2017年

作者： Xiong, Siqing Wang, Lijun Kwak, Kyung Sup Bai, Zhiquan Wang, Jiang Li, Qiang Han, Tao School of Electronic Information and Communications Huazhong University of Science and Technology Wuhan China School of Electronic Information Wuhan University Wuhan China Faculty of information science and technology Wenhua College Wuhan China Department of Information and Communication Inha university Incheon Korea Republic of School of Information Science and Engineering Shandong University Jinan China Shanghai Research Center for Wireless Communications Shanghai China Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai China Key lab of wireless sensor network and communication Chinese Academy of Sciences Shanghai China

—Based on the distinguishing features of multi-tier millimeter wave (mmWave) networks such as different transmit powers, different directivity gains from directional beamforming alignment and path loss laws for line-of-sight (LOS) and non-line-of-sight (NLOS) links, we introduce a normalization model to simplify the analysis of multi-tier mmWave cellular networks. The highlight of the model is that we convert a multi-tier mmWave cellular network into a single-tier mmWave network, where all the base stations (BSs) have the same normalized transmit power 1 and the densities of BSs scaled by LOS or NLOS scaling factors respectively follow piecewise constant function which has multiple demarcation points. On this basis, expressions for computing the coverage probability are obtained in general case with beamforming alignment errors and the special case with perfect beamforming alignment in the communication. According to corresponding numerical exploration, we conclude that the normalization model for multi-tier mmWave cellular networks fully meets requirements of network performance analysis, and it is simpler and clearer than the untransformed model. Besides, an unexpected but sensible finding is that there is an optimal beam width that maximizes coverage probability in the case with beamforming alignment errors. Copyright © 2017, The Authors. All rights reserved.

关键词： wireless networks

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A New Fragmentation Strategy for Video of HTTP Live Streaming

A New Fragmentation Strategy for Video of HTTP Live Streamin...

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International Conference on Mobile Ad-hoc and sensor networks, MSN

作者： Xiaorui Li Lei Wang Jingwu Cui Baoyu Zheng National Mobile Communications Research Laboratory Southeast University Nanjing China Key Lab of Broadband Wireless Communication and Sensor Network Technology (NUPT) Nanjing China

ISBN: (纸本)9781509056972

To achieve the flexible and efficient transmission of files in the video on demand system, this paper proposed a three-tier fragmentation strategy which provided a unfiled method of fragmentation for video of HTTP Live Streaming and large file. In order to prove the rationality of the three-tier fragmentation strategy, we compared it with the two layers fragmentation strategy and the fragmentation strategy of equal time. And the comparisons proved the superiority of three-tier fragmentation strategy.

关键词： Peer-to-peer computing IPTV Packet loss Video on demand Data communication

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Design of P2P Application Layer Protocol

Design of P2P Application Layer Protocol

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International Conference on Mobile Ad-hoc and sensor networks, MSN

作者： Yujie Ma Lei Wang Jingwu Cui Baoyu Zheng National Mobile Communications Research Laboratory Southeast University Nanjing China Network Technology (NUPT) Key Lab of Broadband Wireless Communication and Sensor Nanjing China

ISBN: (纸本)9781509056972

On the basis of studying the principle and application technology of P2P protocol, we design the private protocol of P2P application layer to meet the needs of P2P communication. This application layer protocol splits up video into three types of blocks in order to improve transmission efficiency. Besides, the protocol can be expanded when needed since there are some invalid bits in the state list.

关键词： Peer-to-peer computing Protocols Streaming media Authentication Servers Sockets Law

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Channel measurement and modeling for the 15-GHz radio band in an indoor corridor environment

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Journal of communications and Information networks 2016年第2期1卷 102-108页

作者： XU Hui ZHANG Wuxiong YANG Yang Key Lab of Wireless Sensor Network and Communication Chinese Academy of SciencesShanghai 200050China Shanghai Institute of Microsystem and Information Technology Chinese Academy of SciencesShanghai 200050China Shanghai Research Center for Wireless Communications Shanghai 201210China

Traditional mobile communication systems mainly work on the licensed frequency band near or below 3 GHz;however,this band is becoming increasingly *** the other hand,there are abundant unlicensed spectrum resources in higher frequency bands,e.g.,6 GHz,15 GHz,and 28 GHz,and if those bands are applied,the current spectrum shortage problem could be effectively ***,the wireless channel characteristics and models are important but still unknown,and thus in this study,extensive measurements and modeling have been conducted to study the characteristics of the high-frequency 15-GHz ***,a PN(Pseudo Noise)sequence based time-domain measurement system was built and applied to measure the propagation characteristics of the LOS(Line-of-Sight)and NLOS(Non-Line-of-Sight)scenarios in an indoor corridor at 15 ***,in-depth analysis and modeling on the large-scale characteristics of wireless channels,the relationship between distance and path loss,the path loss exponent,and the shadow fading standard variance are ***,the relationship between received power and different elevation angles was *** the measurement,two 25-dBi horn antennas with a 10 half-power beam width are used to change elevation angles in the transmitting terminal and azimuth angles in the receiving terminal for all measurement *** findings and results in this work will serve as a reference and basis for future theoretical studies of the 15-GHz band.

关键词： 5G mobile network 15 GHz high frequency channel measurement channel modeling

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Sleeping-time Analysis for Cognitive OFDM-PON

Sleeping-time Analysis for Cognitive OFDM-PON

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International Conference on wireless communications and Signal Processing

作者： Qiang Yu Xiaoting Yu Xiao Wu Lei Wang Baoyu Zheng Global Energy Interconnection Research institute Key Lab of Broadband Wireless Communication and Sensor Network Technology (NUPT) National Mobile Communications Research Laboratory Southeast University

ISBN: (纸本)9781509028610

In this paper, we introduce the concept of OFDM-PON, and introduce the best method to choose the maximum sleep time based on link speed and queue buffer capacity. By analyzing the relationship between the longest sleep time and the queue buffer capacity, it is concluded that inducing cognition into OFDM-PON can be used as an effective method to improve the energy efficiency.

关键词： Cognition OFDM-PON Sleeping time Link speed Queue buffer capacity

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