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arXiv 2018年

作者： Li, Wei Zhao, Shengmei Nanjing University of Posts and Telecommunications Institute of Signal Processing and Transmission Nanjing210003 China Nanjing University of Posts and Telecommunications Key Lab Broadband Wireless Communication and Sensor Network Ministy of Education Nanjing210003 China Sunwave Communications Hangzhou310053

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Comparative Channel Study of Ray Tracing and Measurement for an Indoor Scenario at 28 GHz

Comparative Channel Study of Ray Tracing and Measurement for...

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European Conference on Antennas and Propagation

作者： Jinnan Zhan Jianhua Zhang Lei Tian Xinzhuang Zhang Pan Tang Jianwu Dou Hewen Wei Key Lab of Universal Wireless Communications Ministry of Education State Key Lab of Networking and Switching Technology Beijing University of Posts and Telecommunications Mailbox NO.92 100876 Beijing China Wireless Algorithm Department Product R&D system ZTE Corp. Ltd. 201210 Shanghai China National Key Laboratory of Science and Technology on Blind Signal Processing 610041 Chengdu Sichuan China

The millimeter wave communication is important for future wireless systems. In this paper, the channel characteristics at 28 GHz in an indoor scenario are researched based on ray tracing (RT) simulation and measurement. In the RT simulation, various configurations, such as different number of reflections, diffractions and penetrations are used. As for the measurement, two setups are implemented in order to analyze more parameters. Setup one is that biconical antennas are used at both the transmitter (TX) and receiver (RX). The other setup is that horn antenna at RX is rotated 360° in azimuth with a step of 5° when an omni-directional antenna located at TX. Meanwhile, antenna is rotated one circle with an elevation angle of 10°, 0° and -10°, respectively. Path loss and K-factor are analyzed firstly, and analysis results indicate the RT result with 1 or 2 reflections, 1 diffractions and 5 penetrations in this conference room is closest to the measurement result and channel models in 3GPP TR 38.901. Then, the root mean square (RMS) delay spread and RMS angular spread are investigated, which shows the value of measurement is a bit larger than RT because of the limitation of azimuth and elevation step. According to all the results, 1-2 reflections, 1 diffraction and 5 penetrations can be used in RT for future analysis of indoor scenario at 28 GHz.

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Manipulating orbital angular momentum entanglement by using the Heisenberg Uncertainty principle

arXiv

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arXiv 2018年

Orbital angular momentum entanglement is one of the most intriguing topics in quantum physics. A broad range of research have been dedicated either to unravel its underlying physics or to expand the entanglement dimensions and degrees. In this paper, we present a theoretical study on the orbital angular momentum entanglement by employing the Heisenberg uncertainty principle to quantum position correlation within the azimuthal region. In this study, we decompose the pump light into a set of pump cone states characterized by their radii. The OAM entanglement can be manipulated by controlling the radius of the pump cone state, the length of the nonlinear crystal and the OAM carried by the pump field,which is followed by a detailed discussion. We expect that our research will bring us a deeper understanding of the OAM entanglement, and will do help to the high-dimensional quantum information tasks based on OAM entanglement. Copyright © 2018, The Authors. All rights reserved.

关键词： Pumps

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A Two-Stage Allocation Scheme for Delay-Sensitive Services in Dense Vehicular networks

A Two-Stage Allocation Scheme for Delay-Sensitive Services i...

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IEEE International Conference on communications Workshops

作者： Haojun Yang Long Zhao Lei Lei Kan Zheng Wireless Signal Processing and Network (WSPN) Lab Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications (BUPT) State Key Lab of Rail Traffic Control and Safety Beijing Jiaotong University

ISBN: (纸本)9781509015269

Driven by the rapid development of wireless communication system, more and more vehicular services can be efficiently supported via vehicle-to-everything (V2X) communications. In order to allocate radio resource with the reasonable implementation complexity in dense urban intersection, a two-stage allocation algorithm is proposed in this paper, whose main objective is to minimize delay and ensure reliability. In particular, as for the first stage, the allocation policy is based on traffic density information (TDI), which is different from utilizing channel state information (CSI) and queue state information (QSI) in the second stage. Moreover, in order to reflect the influence of TDI on delay, a macroscopic vehicular mobility model is employed in this paper. Simulation results show that the proposed algorithm can acquire an asymptotically optimal performance with the acceptable complexity.

关键词： Low latency and high reliability Radio resource allocation Dense urban intersection Macroscopic mobility model Resource utilization TLX1NB gene Tolylene Diisocyanate wireless communication systems Legal Services Dense Allocation Algorithm order Traffic density

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USER INTEREST BASED DISTRIBUTED COOPERATIVE CACHING AND SHARING IN wireless networkS 5

USER INTEREST BASED DISTRIBUTED COOPERATIVE CACHING AND SHAR...

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2016 5th IEEE International Conference on network Infrastructure and Digital Content(IC-NIDC 2016)

作者： Zheng Guo Hao Jin Chenglin Zhao Dong Liang Wireless Signal Processing and Network Lab Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications

ISBN: (纸本)9781509012473

Distributed cache is considered to be one of the key solutions to meet the explosively increasing demand for mobile data *** plenty of related research is burgeoning,most of them mainly focus on caching at routing nodes or base stations,leaving the potential caching ability of the users’ smart devices *** paper proposes a cooperative caching and sharing scheme of users’ smart devices,where the smart devices would prefer to cache contents the user is interested in and share their cached contents through D2 D *** provide both the analytical and simulation results to show our scheme’s efficiency.

关键词： User cooperation Caching and sharing D2D

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Traffic scenario recognition and analysis for wireless cellular system: From social network perspective

Traffic scenario recognition and analysis for wireless cellu...

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2016 IEEE Canadian Conference on Electrical and Computer Engineering, CCECE 2016

作者： Yi, Zhenglei Peng, Yiran Wang, Tong Zhang, Xing Wang, Wenbo Key Laboratory of Universal Wireless Communication Ministry of Education Wireless Signal Processing and Network Lab Beijing University of Posts and Telecommunications Beijing100876 China

ISBN: (纸本)9781467387217

In wireless cellular system, due to the convergence of user behavior, there usually exists some typical scenarios which exhibit different traffic patterns, e.g. stadium, campus and central business district (CBD). Accurate traffic scenario recognition and analysis will lead to more efficient resource management and better QoS (quality-of-service) provision. In this paper, with the idea of social network analysis, a base station social network (BSSN) based method is proposed to recognize and analyze the typical traffic scenarios in wireless cellular system. Firstly, we construct a BSSN to visualize the hidden relationship between base stations (BSs) by using previously measured spatial-temporal wireless traffic data. Then, a modularity optimization based method is used to discover community structure in BSSN. Analytical results show that each community in BSSN corresponds to a typical wireless scenario with a unique traffic pattern in cellular system. Experimental results illustrate that our proposed BSSN based method is general enough and achieves satisfactory performance in traffic scenario recognition and analysis. © 2016 IEEE.

关键词： Base stations

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Practical decoy-state reference-frame-independent measurement-device-independent quantum key distribution

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Physical Review A 2017年第3期95卷 032309-032309页

作者： Chun-Mei Zhang Jian-Rong Zhu Qin Wang Institute of Signal Processing Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China and Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing 210003 China

Reference-frame-independent measurement-device-independent quantum key distribution (RFI-MDI-QKD) is proposed to remove all possible detector side channel attacks without the alignment of reference frames. Due to unavoidable multiphoton events in practical sources, the decoy-state method is always adopted in real-life QKD systems. Unlike original MDI-QKD (O-MDI-QKD), the characterization on practical decoy-state RFI-MDI-QKD is still absent to date. In this paper, we investigate the performance of practical decoy-state RFI-MDI-QKD at different misalignments of reference frames with full parameter optimization when considering statistical fluctuations, and provide a clear comparison between decoy-state RFI-MDI-QKD and O-MDI-QKD. Simulation results demonstrate that decoy-state RFI-MDI-QKD can exhibit performance comparable to that of O-MDI-QKD in practical scenarios, which is very robust in QKD systems.

关键词： Quantum communication Quantum cryptography

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Obtaining better performance in the measurement-device-independent quantum key distribution with heralded single-photon sources

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Physical Review A 2017年第5期96卷 052337-052337页

作者： Xing-Yu Zhou Chun-Hui Zhang Chun-Mei Zhang Qin Wang Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing 210003 China Key Laboratory of Quantum Information University of Science and Technology of China Hefei 230026 China

Measurement-device-independent quantum key distribution (MDI-QKD) has been widely investigated due to its remarkable advantages on the achievable transmission distance and practical security. However, the relative low key generation rate limits its real-life implementations. In this work, we adopt the newly proposed four-intensity decoy-state scheme [Phys. Rev. A 93, 042324 (2016)] to study the performance of MDI-QKD with heralded single-photon sources (HSPS). Corresponding simulation results demonstrate that the four-intensity decoy-state scheme combining HSPS can drastically improve both the key generation rate and transmission distance in MDI-QKD, which may be very promising in future MDI-QKD systems.

关键词： Quantum cryptography

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A Top-down SCMA Codebook Design Scheme Based on Lattice Theory

A Top-down SCMA Codebook Design Scheme Based on Lattice Theo...

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IEEE Annual International Symposium on Personal, Indoor, and Mobile Radio communications

作者： Haonan Yan Hui Zhao Zhaobiao Lv Haojun Yang Key Laboratory of Universal Wireless Communication Ministry of Education Wireless Signal Processing & Network Lab BUPT

ISBN: (纸本)9781509032556

Recent work on multiple access has shown sparse code multiple access (SCMA) is a promising scheme dealing with massive connection. In SCMA systems, symbol spreading is combined with symbol mapping. The coded bits are directly mapped to the spread symbols, called codewords, according to SCMA codebook. Several codewords are superposed on the same resource. Since codebook is essential to SCMA system performance, this paper aims to present a novel top-down codebook design scheme for SCMA. Firstly, a geometrically uniform top-layer mother constellation with good energy efficiency is proposed based on lattice theory. After dividing the top layer constellation into several bottom layer constellations, we use matrix operation to optimize their distance spectrums. Then a mapping principle between users and resource is proposed to construct the final codewords. Simulation results shows that this top-down codebook outperforms existing schemes in bit error ratio (BER) while sharply reduce the peak to average power ratio (PAPR).

关键词： SCMA Codebook design Top-down Lattice theory PAPR

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Deterministic realization of collective measurements via photonic quantum walks

Deterministic realization of collective measurements via pho...

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第十八届全国量子光学学术会议

作者：侯志博 Jun-Feng Tang Yuan Yuan Kang-Da Wu Guo-Yong Xiang Chuan-Feng Li Guang-Can Guo Jiangwei Shang Huangjun Zhu Jian Li 中科大 Key Laboratory of Quantum Information University of Science and Technology of ChinaCAS Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China Naturwissenschaftlich-Technische Fakult?t Universit?t Siegen Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems School of PhysicsBeijing Institute of Technology Institute for Theoretical Physics University of Cologne Department of Physics and Center for Field Theory and Particle Physics Fudan University State Key Laboratory of Surface Physics Fudan University Collaborative Innovation Center of Advanced Microstructures Institute of Signal Processing Transmission Nanjing University of Posts and Telecommunications Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and TelecommunicationsMinistry of Education

Collective measurements on identically prepared quantum systems can extract more information than local measurements, thereby enhancing information-processing efficiency. Although this nonclassical phenomenon has been known for two decades, it has remained a challenging task to demonstrate the advantage of collective measurements in experiments. Here, we introduce a general recipe for performing deterministic collective measurements on two identically prepared qubits based on quantum walks. Using photonic quantum walks, we realize experimentally an optimized collective measurement with fidelity 0.9946 without post selection. As an application, we achieve the highest tomographic efficiency in qubit state tomography to date. Our work offers an effective recipe for beating the precision limit of local measurements in quantum state tomography and metrology. In addition, our study opens an avenue for harvesting the power of collective measurements in quantum information processing and for exploring the intriguing physics behind this power.

关键词： Deterministic realization of collective measurements via photonic quantum walks

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