Use of multiple antennas at both ends of wireless links is the result of the natural progression of more than four decades of evolution of adaptive antenna technology. Recent advances have demonstrated that multiple- input-multiple-output (MIMO) wireless systems can achieve impressive increases in overall system performance.
标签： Technology System MIMO
上传时间： 2020-05-27
上传用户：shancjb
By definition, the term “mobile-radio communications” describes any radio communication link between two terminals of which one or both are in motion or halted at unspecified locations and of which one may actually be a fixed terminal such as a base station. This definition applies to both mobile-to-mobile and mobile-to-fixed radio communica- tion links. The mobile-to-mobile link could in fact consist of a mobile- to-fixed-to-mobile radio communication link.The term “mobile” applies to land vehicles, ships at sea, aircraft, and communications satellites. In tactical situations, mobile-radio systems may include any or all of these types of mobile terminals.
标签： Communications Engineering Mobile
上传时间： 2020-05-30
上传用户：shancjb
Advances in communication and networking technologies are rapidly making ubiq- uitous network connectivity a reality. Wireless networks are indispensable for supporting such access anywhere and at any time. Among various types of wire- less networks, multihop wireless networks (MWNs) have been attracting increasing attention for decades due to its broad civilian and military applications. Basically, a MWN is a network of nodes connected by wireless communication links. Due to the limited transmission range of the radio, many pairs of nodes in MWNs may not be able to communicate directly, hence they need other intermediate nodes to forward packets for them. Routing in such networks is an important issue and it poses great challenges.
标签： Multihop Wireless Networks
上传时间： 2020-05-30
上传用户：shancjb
Optical wireless communication is an emerging and dynamic research and development area that has generated a vast number of interesting solutions to very complicated communication challenges. For example, high data rate, high capacity and minimum interference links for short-range communication for inter-building communication, computer-to-computer communication, or sensor networks. At the opposite extreme is a long-range link in the order of millions of kilometers in the new mission to Mars and other solar system planets.
标签： Communication Wireless Optical Systems
上传时间： 2020-05-31
上传用户：shancjb
Wireless means different things to different people. For this book, it refers to the radio systems that provide point-to-point, point-to-multipoint, and Earth-space communications over transmission links that propagate outside buildings through the lower atmosphere. Wireless systems are being built that provide data transmission between computers and other devices on one’s own desk. These are part of the wireless world but not the part where, except for interference perhaps, the atmosphere has any influence. The intent of this book is to provide a description of the physical phenomena that can affect propagation through the atmosphere, present sample measurements and statistics, and provide models that system designers can use to calculate their link budgets and estimate the limitations the atmosphere may place on their design.
标签： Communication Propagation Handbook Wireless for
上传时间： 2020-05-31
上传用户：shancjb
A wireless communication network can be viewed as a collection of nodes, located in some domain, which can in turn be transmitters or receivers (depending on the network considered, nodes may be mobile users, base stations in a cellular network, access points of a WiFi mesh etc.). At a given time, several nodes transmit simultaneously, each toward its own receiver. Each transmitter–receiver pair requires its own wireless link. The signal received from the link transmitter may be jammed by the signals received from the other transmitters. Even in the simplest model where the signal power radiated from a point decays in an isotropic way with Euclidean distance, the geometry of the locations of the nodes plays a key role since it determines the signal to interference and noise ratio (SINR) at each receiver and hence the possibility of establishing simultaneously this collection of links at a given bit rate. The interference seen by a receiver is the sum of the signal powers received from all transmitters, except its own transmitter.
标签： Stochastic Geometry Networks Wireless Volume and II
上传时间： 2020-05-31
上传用户：shancjb
A mobile ad-hoc network (MANET) is formed by multiple moving nodes equipped with wireless transceivers. The mobile nodes communicate with each other through multi-hop wireless links, where every node can transmit and receive information. Mobile ad-hoc networks have become increasingly important in areas where deployment of communications infrastructure is difficult.
标签： Telecommunications Modeling
上传时间： 2020-06-01
上传用户：shancjb
Having dealt with in-depth analysis of SS#7, GSM and GPRS networks I started to monitor UTRAN interfaces approximately four years ago. Monitoring interfaces means decoding the data captured on the links and analysing how the different data segments and messages are related to each other. In general I wanted to trace all messages belonging to a single call to prove if the network elements and protocol entities involved worked fine or if there had been failures or if any kind of suspicious events had influenced the normal call proceeding or the call’s quality of service. Cases showing normal network behaviour have been documented in Kreher and Ruedebusch (UMTS Signaling. John Wiley & Sons, Ltd, 2005), which provides examples for technical experts investigating call flows and network procedures.
标签： Performance Measurement Practical Guide UMTS
上传时间： 2020-06-01
上传用户：shancjb
首先下载软件，解压软件，安装在程序中找到SEGGER,选里面的J-FLASH，进入界面，刚开始的那个界面可以忽略，不用建project也可以；单击菜单栏的“Options---Project settings”打开设置，进行jlink配置;正在General选项，选择“USB”，一般都是默认配置，确认一下即可;然后在CPU选项，选择芯片型号，先选择“Device”才能选择芯片型号，芯片型号，要根据你使用的芯片进行选择;在Target interface选项 里面选择SWD模式;首先Target里面选“Connection”连接目标芯片，然后 Target--Auto进行程序烧写;首先Target里面选择“Connection”连接目标芯片，然后 Target--Auto进行程序烧写.SEGGER J-links are the most widely used line of debug probes available today. They've proven their value for more than 10 years in embedded development. This popularity stems from the unparalleled performance, extensive feature set, large number of supported CPUs, and compatibility with all popular development environments.
标签： JLINK
上传时间： 2022-03-22
上传用户：yb9018
AD17是一款十分出色的专业化PCB电路设计工具，Altium Designer 2017功能强劲，为用户提供了全新的PCB布线及增强技术、动态铺铜、自动交叉搜索等功能，AD17操作简便，能够帮助用户轻松地将自己从干扰设计工作的琐碎任务中解放出来，从而完全专注于设计本身。AD17软件介绍 AD17是一款简单易用、原生3D设计增强的一体化设计环境，它结合了原理图、ECAD库、规则和限制条件、BoM、供应链管理、ECO流程和世界一流的PCB设计工具。从概念到完成产品，您的设计过程可以分解为若干个不同的阶段，这些阶段需要保持一致性和连接性。利用Altium Designer强大的工具，您可以完全掌控设计过程，提高了整个设计团队的生产力和工作效率，为您节省总体成本、缩短产品上市时间，助您一直处于新科技的最前沿。AD17软件特点 1、轻松的设计自动化 1)超级强大的布线技术帮助您充分发挥设计潜力 从复杂的电路板布局到创新的可穿戴技术，altium designer 17可以非常很容易地设计出有效无误的PCB板。凭借强大的布线技术，包括交互式布线模式和智能自动完成助手，您可以完全掌控PCB设计。 2)领先一步开始下一个设计工程 今天的设计是建立在过去成功的设计基础之上的。通过altium designer 17中最高效的设计复用工具，帮助您发掘真正的设计潜力。轻松保存、共享和复用一切最值得信赖的设计资产，包括设计片段、受管的原理图图纸、公司的元器件库和模板等。 3)轻松完成您的设计之旅 从概念到完成产品，您的设计过程可以分解为若干个不同的阶段，这些阶段需要保持一致性和连接性。利用altium designer 17强大的发布管理工具，您可以完全掌控设计过程。利用灵活的输出文档管理工具，您可以即时向制造商传达完整的设计意图。 2、直观的团队协作 1)创造未来的柔性设计技术 要想在瞬息万变的电子设计领域中生存下去，您需要一直站在变化的最前沿，来保持设计竞争力。通过业界第一款也是唯一一款支持刚柔结合PCB设计的Altium Designer工具，设计当前最具创新性的产品。轻松地定义材料选择，智能地完成刚柔结合板的布局和布线，在美观的、原生3D PCB中展现您的工程艺术作品。 2)规范并集中管理您最有价值的设计资产 设计过程的成功取决于所使用元器件的数据完整性、可靠性和一致性。通过Altium Designer的集中元器件库管理功能 ，可以建立一个来源唯一的、可信赖的、由整个设计团队共享的元器件库。您可以在未来所有的项目中，立刻使用、管控和复用所有有价值的元器件。 3)在机械世界可视化和验证您的电子设计 任何电子设计产品都要安装在机械物理实体之中。通过altium designer 17的原生3D可视化与间距检查功能，确保电路板在第一次安装时即可与外壳完美匹配，不再需要昂贵的设计返工。在3D编辑状态下，电路板与外壳的匹配情况可以实时展现，您可以在几秒钟内解决电路板与外壳之间的 3、广阔的工程应用范围 1)将您的设计与动态、智能的数据相连 最佳的元器件是，需要的时候就能够买到，并且价格还符合您的预算要求。使用altium designer 17的Supplier links功能，可以从信赖的供应商那里获得丰富的元器件实时定价和可用性数据。即时获得常用元器件的价格和库存信息，您不再会因为买不到元器件而推迟产品发布日期了。 2)掌控设计数据和工作流程的效率 设计过程的成功取决于一系列单独但密切相关的细节。通过altium designer 17强大的数据管理工具，掌控您的设计数据和工作流程。使用灵活的生命周期管理系统，可以精确地控制设计数据;使用强大的版本控制系统，可以跟踪每一个设计变更。 3)发掘专业创建设计内容的潜力 无需从头开始进行所有的PCB设计，您可以直接利用Altium建库专家们的知识和经验。访问Altium公司提供的超过300000个免费元器件，提高元器件的创建效率。充分利用Altium专业制作专业管理的统一元器件库内容，节省创建和管理元器件库的时间。
上传时间： 2022-07-22
上传用户：canderile
