Notwithstanding its infancy, wireless mesh networking (WMN) is a hot and growing field. Wireless mesh NetWorks began in the military, but have since become of great interest for commercial use in the last decade, both in local area NetWorks and metropolitan area NetWorks. The attractiveness of mesh NetWorks comes from their ability to interconnect either mobile or fixed devices with radio interfaces, to share information dynamically, or simply to extend range through multi-hopping.
标签： Multi-hop NetWorks WiMAX WiFi Mesh LTE and
上传时间： 2020-06-01
上传用户：shancjb
Wireless networking is undergoing a transformation from what has been primarily a medium for supporting voice traffic between telephones, into what is increasingly becoming a medium for supporting traffic among a variety of digital devices transmitting media of many types (voice, data, images, video. etc.) Wireline networking underwent a similar transformation in the 1990s, which led to an enormous build-up in the capacity of such NetWorks, primarily through the addition of new optical fiber, switches and other infrastructure.
标签： Multiusers Detection Wireless NetWorks
上传时间： 2020-06-01
上传用户：shancjb
Resource allocation is an important issue in wireless communication NetWorks. In recent decades, cognitive radio technology and cognitive radio-based NetWorks have obtained more and more attention and have been well studied to improve spectrum utilization and to overcomethe problem of spectrum scarcity in future wireless com- munication systems. Many new challenges on resource allocation appear in cogni- tive radio-based NetWorks. In this book, we focus on effective solutions to resource allocation in several important cognitive radio-based NetWorks, including a cogni- tive radio-basedopportunisticspectrum access network, a cognitiveradio-basedcen- tralized network, a cognitive radio-based cellular network, a cognitive radio-based high-speed vehicle network, and a cognitive radio-based smart grid.
上传时间： 2020-06-07
上传用户：shancjb
This book is the result of works dedicated to specific applications of metaheuristics in smart electrical grids. From electric transmission, distribution NetWorks to electric microgrids, the notion of intelligence refers to the ability to propose acceptable solutions in an increasingly more restrictive environment. Most often, it refers to decision-making assisting tools designed to support all human action.
标签： Metaheuristics Intelligent Electrical NetWorks for
上传时间： 2020-06-07
上传用户：shancjb
Recent work has shown that convolutional NetWorks can be substantially deeper, more accurate, and efficient to train if they contain shorter connections between layers close to the input and those close to the output. In this paper, we embrace this observation and introduce the Dense Convo- lutional Network (DenseNet), which connects each layer to every other layer in a feed-forward fashion.
标签： Convolutional Connected NetWorks Densely
上传时间： 2020-06-10
上传用户：shancjb
近几年来，OFDM(Orthogonal Frequency Division Multiplexing)技术引起了人们的广泛注意，根据这项新技术，很多相关协议被提出来。其中WiMax(Wireless MetropolitanArea NetWorks)代表空中接口满足IEEE 802.16标准的宽带无线通信系统，IEEE标准在2004年定义了空中接口的物理层(PHY)，即802.16d协议。该协议规定数据传输采用突发模式，调制方式采用OFDM技术，传输速率较高且实现方便、成本低廉，已经成为首先推广应用的商业化标准。 本文主要对IEEE802.16d OFDM系统物理层进行研究，并在XILINX公司的Virtexpro II芯片上实现了基带算法。 首先讨论了OFDM基本原理及其关键技术。根据IEEE802.16d OFDM系统的物理层发送端流程搭建了基带仿真链路，利用MATLAB/SIMULINK仿真了OFDM系统在有无循环前缀(CP)、多径数目不同等情况下的性能变化。由于同步算法和信道估计算法计算量都很大，为了找到适合采用FPGA实现的算法，分析了同步误差和不同信道估计算法对接收信号的影响，并结合计算量的大小提出了一种新的联合同步算法，以及得出了LS信道估计算法最适合802.16d系统的结论。 其次，完成了基带发射机和接收机的FPGA硬件电路实现。为了使系统的时钟频率更高，采用了流水线的结构。设计中采用编写Verilog程序和使用IP核相结合的办法，实现了新的联合同步算法，并且通过简化结构，避免了信道估计算法中的繁琐除法。利用ISE9. 2i和Modelsim6.Oc软件平台对程序进行设计、综合和仿真，并将仿真结果和MATLAB软件计算结果相对比。结果表明，采用16位数据总线可达到理想的精度。 最后，采用串口通信的方式对基带系统进行了验证。通过串口通信从功能上表明该系统确实可行。 关键词：IEEE802. 16d； OFDM； 同步；信道估计；基带系统
上传时间： 2013-07-31
上传用户：1757122702
无线传感器网络（Wireless Sensor NetWorks，WSN）是由大量传感器节点组成，这些节点部署在监测区域内通过无线通信方式，形成的一个多跳自组织的网络。整个网络的作用是协作地感知、采集和处理网络覆盖区域中监测对象的信息，并发送给观察者，可广泛应用于环境监测、医疗护理、军事、商业等多个领域。 媒体访问控制（Medium Access Control，MAC）协议处于无线传感器网络协议的物理层和路由层之间，用于在传感器节点间公平有效地共享通信媒介，对传感器网络的性能有较大影响。与传统无线网络不同，提高能量效率和可扩展性是无线传感器网络MAC协议设计的主要目标。 本文主要阐述基于FPGA对IEEE802．15．4 MAC层功能的实现。首先介绍了无线传感器网络的体系结构、MAC协议的设计要求以及已有的MAC层协议，讨论了无线传感器网络MAC层的主要要求和功能。然后详细介绍和分析了IEEE802．15．4的MAC协议，并在此基础上，通过NS2平台对MAC层协议进行了仿真，研究不同网络负荷下信道访问机制的各个参数对吞吐量，丢包率，传输延时的影响，分析了隐蔽站问题、确认帧机制。 本文对MAC层中的主要功能，诸如数据收发、帧处理、信道接入方式以及帧检验等提出了基于FPGA的硬件解决方法。设计选用硬件描述语言VerilogHDL，在QuartusⅡ中完成模块的综合和布局布线，在QuartusⅡ和Modelsim中进行时序仿真验证，最终下载到自主设计Altera公司的Cyclone开发板中。 对设计的验证采取的是由里及外的方式，先对系统主模块的功能进行验证，然后下载到与CC2430开发板相连接的FPGA中对设计进行验证测试。验证流程是功能仿真、时序仿真和板级调试，最终通过测试，验证了该设计的功能。测试结果表明，该模块能满足无线传感器网络低速率应用环境的需要，具有优良的扩展性能，达到了预期的设计目标。
上传时间： 2013-06-14
上传用户：竺羽翎2222
Abstract: It may sound trite, but it is definitely true: the smart grid has the potential to completely transform the energyindustry. However, smart meters and grid management alone will not ensure the success of the smart grid. Unliketraditional IT NetWorks, smart grids require consideration of energy measurement and security. To completely optimize thistechnology, smart grid designs must focus on energy measurement and security. This tutorial considers the benefits ofboth energy measurement and security and how they make machine-to-machine NetWorks different from traditional IT.
上传时间： 2013-10-29
上传用户：皇族传媒
本指南包含有关移除和安装Secure Access 6000机柜中的现场置换单元的信息。 有关Secure Access 6000的安全信息，请参阅Juniper NetWorks支持站点上的Juniper NetWorks Security Products Safety Guide。以下各部分将介绍有关组件的移除和安装的详细过程。
上传时间： 2014-01-25
上传用户：shenlan
Single-Ended and Differential S-Parameters Differential circuits have been important incommunication systems for many years. In the past,differential communication circuits operated at lowfrequencies, where they could be designed andanalyzed using lumped-element models andtechniques. With the frequency of operationincreasing beyond 1GHz, and above 1Gbps fordigital communications, this lumped-elementapproach is no longer valid, because the physicalsize of the circuit approaches the size of awavelength.Distributed models and analysis techniques are nowused instead of lumped-element techniques.Scattering parameters, or S-parameters, have beendeveloped for this purpose [1]. These S-parametersare defined for single-ended NetWorks. S-parameterscan be used to describe differential NetWorks, but astrict definition was not developed until Bockelmanand others addressed this issue [2]. Bockelman’swork also included a study on how to adapt single-ended S-parameters for use with differential circuits[2]. This adaptation, called “mixed-mode S-parameters,” addresses differential and common-mode operation, as well as the conversion betweenthe two modes of operation.This application note will explain the use of single-ended and mixed-mode S-parameters, and the basicconcepts of microwave measurement calibration.
上传时间： 2014-03-25
上传用户：yyyyyyyyyy
