Wireless communications has become a field of enormous scientific and economic interest. Recent success stories include 2G and 3G cellular voice and data services (e.g., GSM and UMTS), wireless local area networks (WiFi/IEEE 802.11x), wireless broadband access (WiMAX/IEEE 802.16x), and digital broadcast systems (DVB, DAB, DRM). On the physical layer side, traditional designs typically assume that the radio channel remains constant for the duration of a data block. However, researchers and system designers are increasingly shifting their attention to channels that may vary within a block. In addition to time dispersion caused by multipath propagation, these rapidly time-varying channels feature frequency dispersion resulting from the Doppler effect. They are, thus, often referred to as being “doubly dispersive.”
标签： Time-Varying Channels
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Visible light communications (VLC) is the name given to an optical wireless communication system that carries information by modulating light in the visible spectrum (400–700 nm) that is principally used for illumination [1–3]. The communications signal is encoded on top of the illumination light. interest in VLC has grown rapidly with the growth of high power light emitting diodes (LEDs) in the visible spectrum. The motivation to use the illumination light for communication is to save energy by exploiting the illumination to carry information and, at the same time, to use technology that is “green” in comparison to radio frequency (RF) technology, while using the existing infrastructure of the lighting system.
标签： Communication Visible Light
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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
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Welcome to the third volume of the book entitled Technologies for the Wireless Future, which is produced by WWRF. The idea is to take the most important outputs from the working groups and special-interest groups that compose the Forum and bring them together in a series of one-volume surveys. The latest of these will give the reader a good overview of the WWRF approach to analyzing the future of wireless and mobile communications, as well as an insight into the trends themselves and the key technologies that will be deployed.
标签： Wireless Research Forum World
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Static electricity is the most ancient form of electricity known to humans. More than 2000 years ago, the Greeks recognized the attraction between certain mate- rials when they were rubbed together; indeed, the word electricity comes from the Greek elektron, which means amber. During the seventeenth and eighteenth centuries, several key experiments were conducted to understand and measure static electricity. But the discovery of electromagnetism and its formidable break- through has rapidly outgrown interest in static electricity. Even today, where the industrial applications of static electricity are not insignificant, they cannot compare with those of electromagnetism and electrodynamics.
标签： Understand Discharge Electro Static
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Electrostatic discharge (ESD) phenomena have been known to mankind since the Greek Empire when Thales of Miletus, one of the Seven Sages of Greece, noticed the attraction of strands of hay to amber, leading to the coining of the word ‘‘electron.’’ In the 17th century, Gilbert and Cabeo addressed the attractive and repulsive nature of electricity. In the 18th century, a rapid increase of interest occurred for scientists in the understanding of electrical physics—Gray, du Fay, Nollet, Musschenbroeck, Franklin, Watson, Aepinus, Canton,
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Electrostatic discharge (ESD) phenomena have been known to mankind since Thales of Miletus in approximately 600 B.C.E. noticed the attraction of strands of hay to amber. Two thousand six hundred years have passed and the quest to obtain a better under- standing of electrostatics and ESD phenomenon continues. Today, the manufacturing of microelectronics has continued the interest in the field of electrostatic phenomenon spanning factory issues, tooling, materials, and the microelectronic industry
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The phenomenon of electrostatic discharge (ESD) has been known for a long time, but recently a growing interest has been observed in ESD in radio frequency (RF) technology and ESD issues in RF applications.
标签： Technology Circuits ESD and RF
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Electrostatic discharge (ESD) phenomena have been known to mankind since the Greek Empire when Thales of Miletus, one of the Seven Sages of Greece, noticed the attraction of strands of hay to amber, leading to the coining of the word “electron.” Electrical discharge and the guiding of electrical discharge (e.g., lightning) was of interest to Benjamin Franklin in the 1700s, with the invention of the lightning rod. The lightning rod was mankind’s first effort to guide the electrical discharge current of a lightning strike in a direction that would not harm structures.
标签： Circuits Devices 2015 ESD and
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This book is based on a Ph.D. research that has been conducted at the Delft University of Technology in the Netherlands in collaboration with Dutch Electricity & Gas Distribution Network Operator, Stedin. This book was written as a result of wider interest that was shown by different industry groups on this topic after its public defence. This inspired the author to modify and publish a practical version of the research for a greater international audience. Therefore, the content of this book is intended for a double audience, on the one hand for those interested in the organisational and management aspects of maintenance.
标签： Maintenance Electricity Risk-Based Network for
上传时间： 2020-06-07
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