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.
標簽： Technology System MIMO
上傳時間： 2020-05-28
上傳用戶：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.
標簽： Communications Engineering Mobile
上傳時間： 2020-05-30
上傳用戶：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.
標簽： Multihop Wireless Networks
上傳時間： 2020-05-31
上傳用戶：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.
標簽： Communication Wireless Optical Systems
上傳時間： 2020-05-31
上傳用戶：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.
標簽： Communication Propagation Handbook Wireless for
上傳時間： 2020-05-31
上傳用戶：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.
標簽： Stochastic Geometry Networks Wireless Volume and II
上傳時間： 2020-06-01
上傳用戶：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.
標簽： Telecommunications Modeling
上傳時間： 2020-06-01
上傳用戶：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.
標簽： Performance Measurement Practical Guide UMTS
上傳時間： 2020-06-01
上傳用戶：shancjb
首先下載軟件，解壓軟件，安裝在程序中找到SEGGER,選里面的J-FLASH，進入界面，剛開始的那個界面可以忽略，不用建project也可以；單擊菜單欄的“Options---Project settings”打開設置，進行jlink配置;正在General選項，選擇“USB”，一般都是默認配置，確認一下即可;然后在CPU選項，選擇芯片型號，先選擇“Device”才能選擇芯片型號，芯片型號，要根據你使用的芯片進行選擇;在Target interface選項 里面選擇SWD模式;首先Target里面選“Connection”連接目標芯片，然后 Target--Auto進行程序燒寫;首先Target里面選擇“Connection”連接目標芯片，然后 Target--Auto進行程序燒寫.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.
標簽： JLINK
上傳時間： 2022-03-22
上傳用戶：
AD17是一款十分出色的專業化PCB電路設計工具，Altium Designer 2017功能強勁，為用戶提供了全新的PCB布線及增強技術、動態鋪銅、自動交叉搜索等功能，AD17操作簡便，能夠幫助用戶輕松地將自己從干擾設計工作的瑣碎任務中解放出來，從而完全專注于設計本身。AD17軟件介紹 AD17是一款簡單易用、原生3D設計增強的一體化設計環境，它結合了原理圖、ECAD庫、規則和限制條件、BoM、供應鏈管理、ECO流程和世界一流的PCB設計工具。從概念到完成產品，您的設計過程可以分解為若干個不同的階段，這些階段需要保持一致性和連接性。利用Altium Designer強大的工具，您可以完全掌控設計過程，提高了整個設計團隊的生產力和工作效率，為您節省總體成本、縮短產品上市時間，助您一直處于新科技的最前沿。AD17軟件特點 1、輕松的設計自動化 1)超級強大的布線技術幫助您充分發揮設計潛力 從復雜的電路板布局到創新的可穿戴技術，altium designer 17可以非常很容易地設計出有效無誤的PCB板。憑借強大的布線技術，包括交互式布線模式和智能自動完成助手，您可以完全掌控PCB設計。 2)領先一步開始下一個設計工程 今天的設計是建立在過去成功的設計基礎之上的。通過altium designer 17中最高效的設計復用工具，幫助您發掘真正的設計潛力。輕松保存、共享和復用一切最值得信賴的設計資產，包括設計片段、受管的原理圖圖紙、公司的元器件庫和模板等?！ ?)輕松完成您的設計之旅 從概念到完成產品，您的設計過程可以分解為若干個不同的階段，這些階段需要保持一致性和連接性。利用altium designer 17強大的發布管理工具，您可以完全掌控設計過程。利用靈活的輸出文檔管理工具，您可以即時向制造商傳達完整的設計意圖?！ ?、直觀的團隊協作 1)創造未來的柔性設計技術 要想在瞬息萬變的電子設計領域中生存下去，您需要一直站在變化的最前沿，來保持設計競爭力。通過業界第一款也是唯一一款支持剛柔結合PCB設計的Altium Designer工具，設計當前最具創新性的產品。輕松地定義材料選擇，智能地完成剛柔結合板的布局和布線，在美觀的、原生3D PCB中展現您的工程藝術作品。 2)規范并集中管理您最有價值的設計資產 設計過程的成功取決于所使用元器件的數據完整性、可靠性和一致性。通過Altium Designer的集中元器件庫管理功能 ，可以建立一個來源唯一的、可信賴的、由整個設計團隊共享的元器件庫。您可以在未來所有的項目中，立刻使用、管控和復用所有有價值的元器件?！ ?)在機械世界可視化和驗證您的電子設計 任何電子設計產品都要安裝在機械物理實體之中。通過altium designer 17的原生3D可視化與間距檢查功能，確保電路板在第一次安裝時即可與外殼完美匹配，不再需要昂貴的設計返工。在3D編輯狀態下，電路板與外殼的匹配情況可以實時展現，您可以在幾秒鐘內解決電路板與外殼之間的 3、廣闊的工程應用范圍 1)將您的設計與動態、智能的數據相連 最佳的元器件是，需要的時候就能夠買到，并且價格還符合您的預算要求。使用altium designer 17的Supplier links功能，可以從信賴的供應商那里獲得豐富的元器件實時定價和可用性數據。即時獲得常用元器件的價格和庫存信息，您不再會因為買不到元器件而推遲產品發布日期了?！ ?)掌控設計數據和工作流程的效率 設計過程的成功取決于一系列單獨但密切相關的細節。通過altium designer 17強大的數據管理工具，掌控您的設計數據和工作流程。使用靈活的生命周期管理系統，可以精確地控制設計數據;使用強大的版本控制系統，可以跟蹤每一個設計變更。 3)發掘專業創建設計內容的潛力 無需從頭開始進行所有的PCB設計，您可以直接利用Altium建庫專家們的知識和經驗。訪問Altium公司提供的超過300000個免費元器件，提高元器件的創建效率。充分利用Altium專業制作專業管理的統一元器件庫內容，節省創建和管理元器件庫的時間。
上傳時間： 2022-07-22
上傳用戶：canderile
