检索结果-内蒙古大学图书馆

7th IET International Conference on wireless, Mobile and Multimedia networks, ICWMMN 2017

作者： Hu, Han Wang, Hong Yang, Jie Pan, Ziyu 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 Jiangsu Nanjing210003 China Communication Engineering Department Nanjing Institute of Technology Jiangsu Nanjing211167 China

ISBN: (纸本)9781785615153

In this paper, an analytical framework is developed to evaluate the uplink outage and spatial blocking performance in a multichannel heterogeneous cellular network. A weighted uplink cell association criterion and random channel reuse scheme are integrated in the considered model. The spatial locations of base stations (BSs) per tier as well as the users (UEs) are modelled as independent Poisson point processes. Because of the maximum transmit power constraint, a UE is allowed to communicate with its serving BS only when it has sufficient transmit power to support full channel inversion. With the aid of stochastic geometry, uplink spatial blocking and outage probability are respectively derived, which are validated to be quite close to the true distributions by extensive simulations. Thus, the theoretical analysis developed in this paper is valid. Then, the effect of network parameters, such as weighted factor, power cut-off threshold, and channel reuse factor, can be evaluated by quickly closed-form expressions rather than error-prone system-level simulations. © Institution of Engineering and technology. All rights reserved.

关键词： Outages

来源：评论

学校读者我要写书评

暂无评论

A fast covariance matrix reconstruction method for two-dimensional direction-of-arrival estimation

A fast covariance matrix reconstruction method for two-dimen...

引用

2017 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2017

作者： Wu, Xiaohuan Zhu, Wei-Ping Yan, Jun Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Nanjing China Department of Electrical and Computer Engineering Concordia University Montreal Canada

ISBN: (纸本)9781509041176

In this paper, a new method for two-dimensional (2-D) direction-of-arrival (DOA) estimation is proposed. We first reconstruct the covariance matrix of the coarray with block-Toeplitz structure and then retrieve the DOAs. Our method is computationally efficient as supported by the derived closed-form expression for the estimated covariance matrix. Unlike other methods, which require fully loaded arrays, the proposed method can be applied in the case of common rectangular arrays with arbitrary geometries. The estimated azimuth and elevation angles are automatically paired. Moreover, our method is of high estimation accuracy and immune to the angle ambiguity effect. Numerical simulations are carried out to verify the effectiveness of the proposed method. © 2017 IEEE.

关键词： 2-D DOA estimation generalized rectangular array (GRA) Toeplitz-block-Toeplitz structure

来源：评论

学校读者我要写书评

暂无评论

Secrecy analysis of full-duplex power-splitting SWIPT networks with artificial noise 7

Secrecy analysis of full-duplex power-splitting SWIPT networ...

引用

2017 7th International Workshop on Computer Science and Engineering, WCSE 2017

作者： Tang, Xuanxuan Yang, Wendong Cai, Yueming Yang, Weiwei Cao, Kuo Yuan, Pan College of Communications Engineering PLA University of Science and Technology Nanjing China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Post and Telecommunications Ministry of Education China

ISBN: (纸本)9789811136719

This work conducts the secrecy analysis of full-duplex power-splitting simultaneous wireless information and power transfer networks with artificial noise. The exact closed-form expressions of the COP, SOP and RSP are derived, respectively, which are illustrated by numerical analysis. The results depict the significance of the power-splitting ratio and the transmit signal-to-noise ratio (SNR). To be specific, the secrecy performance is greatly improved with the increasing of the power-splitting ratio. In addition, it is observed that the security of the system will get enhanced with the increasing of the power-splitting ratio at first and then get reversed for a certain transmit SNR. Moreover, the value of the optimum transmit SNR changes with different transmit SNR.

关键词： Signal to noise ratio

来源：评论

学校读者我要写书评

暂无评论

Efficient separating orbital angular momentum mode with radial varying phase

引用

Photonics Research 2017年第4期5卷 267-270页

作者： CHENG LI SHENGMEI ZHAO Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education

It is shown that orbital angular momentum(OAM) is a promising new resource in future classical and quantum communications. However, the separation of OAM modes is still a big challenge. In this paper, we propose a simple and efficient separation method with a radial varying phase. In the method, specific radial varying phases are designed and modulated for different OAM modes. The resultant beam is focused to the spots with different horizontal and vertical positions after a convex lens, when the coordinate transformation, including two optical elements with coordinate transformation phase and correct phase, operates on the received *** horizontal position of the spot is determined by the vortex phases, and the vertical position of the spot is dependent on the radial varying phases. The simulation and experimental results show that the proposed method is feasible both for separation of two OAM modes and separation of three OAM modes. The proposed separation method is available in principle for any neighboring OAM modes because the radial varying phase is controlled. Additionally, no extra instruments are introduced, and there is no diffraction and narrowing process limitation for the separation.

关键词： OAM Efficient separating orbital angular momentum mode with radial varying phase mode

来源：评论

学校读者我要写书评

暂无评论

A Toeplitz Covariance Matrix Reconstruction Approach for Direction-of-Arrival Estimation

A Toeplitz Covariance Matrix Reconstruction Approach for Dir...

引用

作者： Wu, Xiaohuan Zhu, Wei-Ping Yan, Jun Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Nanjing210003 China Department of Electrical and Computer Engineering Concordia University Montreal QC210003 Canada

It is known that there exist two kinds of methods for direction-of-arrival (DOA) estimation in the literature: the subspace-based method and the sparsity-based method. However, pervious works reveal that the former method cannot address the case in which the number of signals is larger than that of sensors, whereas the latter one always suffers from the influence of basis mismatch. In this paper, to overcome these two shortcomings, we propose a new method called covariance matrix reconstruction approach (CMRA) for both uniform linear array and sparse linear array. In particular, by exploiting the Toeplitz structure of the covariance matrix of the array output, we formulate a low-rank matrix reconstruction (LRMR) problem for covariance matrix recovery. The nonconvex LRMR problem is then relaxed by replacing the rank norm with the nuclear norm and solved using the optimization toolbox. Next, we retrieve the DOAs from the recovered covariance matrix by using the subspace-based methods and obtain an estimated number of signals as a byproduct. We also provide two algorithm implementations for the LRMR problem based on duality and alternating direction method of multipliers, respectively. It is shown that CMRA can be regarded as an atomic norm minimization model or a gridless version of the sparsity-based methods and can recover more signals than sensors with a well-designed array. Numerical experiments are provided to validate the effectiveness of the proposed method, in comparison with some of the existing methods. © 1967-2012 IEEE.

关键词： Covariance matrix

来源：评论

学校读者我要写书评

暂无评论

Dynamic priority algorithm for modern tram based on MADM 2

Dynamic priority algorithm for modern tram based on MADM

引用

2nd IEEE International Conference on Intelligent Transportation Engineering, ICITE 2017

作者： Wu, Jiaqi Yu, Yang Lin, Xiaoyong College of Transportation Science and Technology Nanjing Tech University Nanjing210009 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing210003 China

ISBN: (纸本)9781509062720

Analyzing the influence on traffic flow at intersection according to the driving characteristics of modern tram with different lane layout types. Proposing a method of dynamic priority algorithm (DPA) based on the idea of multiple attribute decision making (MADM) to analyze intersection delay. The VAP module based on MATlab in Vissim is used to simulate the induction control of the modern tram through the concrete intersection, mainly analyzing delay of the intersection with different lane layout types of modern trams. Taking the intersection of Middle Jiangdong Road and Hexi Avenue in Nanjing as an example, the traffic delay caused by different lane layout of modern tram is analyzed by using absolute priority and dynamic priority algorithm (DPA) respectively. © 2017 IEEE.

关键词： MATlab

来源：评论

学校读者我要写书评

暂无评论

Adaptive spatial modulation for visible light communications with an arbitrary number of transmitters

arXiv

引用

arXiv 2018年

作者： Wang, Jin-Yuan Ge, Hong Zhu, Jian-Xia Wang, Jun-Bo Dai, Jianxin Lin, Min Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Nanjing210003 China National Mobile Communications Research Laboratory Southeast University Nanjing210096 China School of Science Nanjing University of Posts and Telecommunications Nanjing210003 China

As a power and bandwidth efficient modulation scheme, the optical spatial modulation (SM) technique has recently drawn increased attention in the field of visible light communications (VLC). To guarantee the number of bits mapped by the transmitter's index at each timeslot is an integer, the number of transmitters (i.e., light-emitting diodes) in the SM based VLC system is often set be a power of two. To break the limitation on the required number of transmitters and provide more design flexibility, this paper investigates the SM based VLC with an arbitrary number of transmitters. Initially, a channel adaptive bit mapping (CABM) scheme is proposed, which includes three steps: Bit mapping in space domain, bit mapping in signal domain, and the channel adaptive mapping. The proposed CABM scheme allows operation with an arbitrary number of transmitters, and is verified to be an efficient scheme through numerical results. Based on the CABM scheme, the information-theoretical aspects of the SM based VLC are analyzed. The theoretical expression of the mutual information is first analyzed. However, it is very hard to evaluate system performance. To obtain more insights, a lower bound of the mutual information is derived, which is in closedform. Both theoretical analysis and numerical results show that the gap between the mutual information and its lower bound is small. Finally, to further improve the system performance, the precoding scheme is proposed for the SM based VLC. Numerical results show that the system performance improves dramatically when using the proposed precoding scheme. Copyright © 2018, The Authors. All rights reserved.

关键词： Visible light communication

来源：评论

学校读者我要写书评

暂无评论

Layered Compression Scheme for Efficient Data Collection of sensory Data

Layered Compression Scheme for Efficient Data Collection of ...

引用

International Conference on Computer communication and networks

作者： Siguang Chen Shujun Zhang Bin Xu Jing Hu Vijayakumar Varadarajan Jiangsu Engineering Research Center of Communication and Network Technology Nanjing University of Posts and Telecommunications Nanjing China Key Lab of Broadband Wireless Communication and Sensor Network Technology of Ministry of Education Nanjing University of Posts and Telecommunications Nanjing China Information Center Jiangsu China Tobacco Industry Co. Ltd. Nanjing China School of Computing Science and Engineering VIT University Chennai India

Although the existing compressed sensing (CS) based spatio-temporal data compression schemes can significantly decrease communication consumption for data collection, they ignore the data correlation among different clusters over spatial dimension. Actually, the discovery and utilization of spatial correlation among different clusters can further increase the compression rate (or improve the recovery effect). In this paper, we propose a layered compression scheme for efficient data collection of sensory data (LCS-EDC). In the proposed scheme, first, we design a multi-layer network architecture to support the exploration of spatio-temporal correlations, especially for exploring the spatial correlation among different clusters. And then, we construct the specific projection methods respectively for exploring the temporal correlation in sensory nodes, spatial correlation (intra-cluster) in cluster heads and spatial correlation (inter-cluster) in processing nodes. Meanwhile, the detailed solving method is developed to recover original data and achieve the approximate data collection in sink node. Finally, simulation results indicate that the proposed layered compression scheme has better recovery performance as compared with traditional clustered compression schemes (i.e., achieving efficient data collection with high quality).

关键词： Compressed sensing data correlation multi-layer architecture data collection recovery error

来源：评论

学校读者我要写书评

暂无评论

An Integrated Optimization Model for Urban Agglomeration Traffic and Land Use Based on Multi-objective Particle Swarm Optimization Algorithm

An Integrated Optimization Model for Urban Agglomeration Tra...

引用

IEEE International Conference on Intelligent Transportation Engineering (ICITE)

作者： Jiaqi Wu Yang Yu Wenqiang Xue Qinyuan Zhang College of Transportation science & Technology Nanjing Tech University Nanjing Key Lab of Broadband Wireless Communication and Sensor Network Technology of Ministry of Education Nanjing University of Posts and Telecommunications Nanjing YangZhou Urban Planning and Research Geography Information Information Center Hexi Campus International Department Jinling High School

Based on the mutual relationship between traffic and land use, the Integrated Transportation and Land Use Model (ITLM) is established from the perspective of urban agglomeration development. The model parameters are calibrated by using MATlab and ArcGIS in combination with information entropy model and Multi-objective Particle Swarm Optimization. From the macro and meso perspectives, the space syntax is used to quantify the transport links of cities in urban agglomerations. Taking the Yangtze River City Group as an example, combined with big data analysis by POI, after optimization of the land use area, population size, and traffic structure of various types of nature through the ITLM model, traffic occurrence and attraction of cities in urban agglomerations tend to be more balanced than the current situation. It plays a vital role in analyzing the current status of cities in urban agglomerations and promoting the further development of urban agglomerations.

关键词： Urban areas Transportation Sociology Statistics Mathematical model Optimization Particle swarm optimization

来源：评论

学校读者我要写书评

暂无评论

Reconfigurable vortex beam generator based on the Fourier transformation principle

arXiv

引用

arXiv 2018年

作者： Liu, Aiping Zou, Chang-Lin Ren, Xifeng He, Wen Wu, Mengze Guo, Guangcan Wang, Qin Affiliation: Institute of Quantum Information and Technology Nanjing University of Posts and Telecommunications Nanjing210003 Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing210003 Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China Hefei230026 China

A method to generate the optical vortex beam with arbitrary superposition of different orders of orbital angular momentum (OAM) on a photonic chip is proposed. The distributed Fourier holographic gratings are proposed to convert the propagating wave in waveguides to a vortex beam in the free space, and the components of different OAMs can be controlled by the amplitude and phases of on-chip incident light based on the principle of Fourier transformation. As an example, we studied a typical device composed of nine Fourier holographic gratings on fan-shaped waveguides. By scalar diffraction calculation, the OAM of the optical beam from the reconfigurable vortex beam generator can be controlled on-demand from ?2nd to 2nd by adjusting the phase of input light fields, which is demonstrated numerically with the fidelity of generated optical vortex beam above 0.69. The working bandwidth of the Fourier holographic grating is about 80 nm with a fidelity above 0.6. Our work provides an feasible method to manipulate the vortex beam or detect arbitrary superposition of OAMs, which can be used in integrated photonics structures for optical trapping, signal processing, and imaging. Copyright © 2018, The Authors. All rights reserved.

关键词： Incident light

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：