Heterogeneous Network (HetNet): A network that consists of a mix of macro cells and low-power nodes, e.g. Pico, Femto, Relay Node (RN) and Remote Radio Head (RRH)
标签: Efficient Spectrum Energy and
上传时间: 2020-06-01
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Recent advances in wireless communication technologies have had a transforma- tive impact on society and have directly contributed to several economic and social aspects of daily life. Increasingly, the untethered exchange of information between devices is becoming a prime requirement for further progress, which is placing an ever greater demand on wireless bandwidth. The ultra wideband (UWB) system marks a major milestone in this progress. Since 2002, when the FCC allowed the unlicensed use of low-power, UWB radio signals in the 3.1–10.6GHz frequency band, there has been significant synergistic advance in this technology at the cir- cuits, architectural and communication systems levels. This technology allows for devices to communicate wirelessly, while coexisting with other users by ensuring that its power density is sufficiently low so that it is perceived as noise to other users.
上传时间: 2020-06-01
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The use of light to send messages is not new. Fires were used for signaling in biblical times, smoke signals have been used for thousands of years and flashing lights have been used to communicate between warships at sea since the days of Lord Nelson. The idea of using glass fibre to carry an optical communications signal originated with Alexander Graham Bell. However this idea had to wait some 80 years for better glasses and low-cost electronics for it to become useful in practical situations.
标签: Communications Understanding Optical
上传时间: 2020-06-01
上传用户:shancjb
Once upon a time, cellular wireless networks provided two basic services: voice telephony and low-rate text messaging. Users in the network were separated by orthogonal multiple access schemes, and cells by generous frequency reuse patterns [1]. Since then, the proliferation of wireless services, fierce competition, andthe emergenceof new service classes such as wireless data and multimediahave resulted in an ever increasing pressure on network operators to use resources in a moreefficient manner.In the contextof wireless networks,two of the most common resources are power and spectrum—and, due to regulations, these resources are typically scarce. Hence, in contrast to wired networks, overprovisioning is not feasible in wireless networks.
标签: Maximization Nonconvex Wireless Utility Systems in
上传时间: 2020-06-01
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This book is concerned with integrated circuits and systems for wireless and mobile communications. Circuit techniques and implementation of reconfigurable low-voltage and low-power single-chip CMOS transceivers for multiband and multi- mode universal wireless communications are the focus of the book. Applications encompass both long-range mobile cellular communications (GSM and UMTS) and short-range wireless LANs (IEEE802.11 and Bluetooth). Recent advances in research into transceiver architecture, RF frontend, analogue baseband, RF CAD and automatic testing are reported.
标签: Communication Wireless Circuits Systems and
上传时间: 2020-06-01
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Digital radios have undergone an astonishing evolution in the last century. Born as a set of simple and power-hungry electrical and electromechanical devices for low data rate transmission of telegraph data in the Marconi age, they have transformed, thanks to substantial advances in electronic technology, into a set of small, reliable and sophisticated integrated devices supporting broadband multimedia communications. This, however, would not have been possible unless significant progress had been made in recent decades in the field of signal processing algorithms for baseband and passband signals. In fact, the core of any modern digital radio consists of a set of algorithms running over programmable electronic hardware. This book stems from the research and teaching activities of its co-authors in the field of algorithmic techniques for wireless communications. A huge body of technical literature has accumulated in the last four decades in this area, and an extensive coverage of all its important aspects in a single textbook is impossible. For this reason, we have selected a few important topics and, for ease of reading, organized them into two parts.
标签: Communications Algorithmic Techniques Wireless
上传时间: 2020-06-01
上传用户:shancjb
Wireless Mesh Networks (WMN) are believed to be a highly promising technology and will play an increasingly important role in future generation wireless mobile networks. WMN is characterized by dynamic self-organization, self-configuration and self-healing to enable quick deployment, easy maintenance, low cost, high scalability and reliable services, as well as enhancing network capacity, connect- ivity and resilience.
标签: Networking Wireless Mesh
上传时间: 2020-06-01
上传用户:shancjb
Nowadays sensors are part of everyday life in a wide variety of fields: scientific applications, medical instrumentation, industrial field, ...and, last but not least, popular mass production and low-cost goods, like smartphones and other mobile devices. Markets and business behind the field of sensors are quite impressive. A common trend for consumer applications is miniaturization which requires, on one side, a lot of research, development efforts, and resources but, on the other hand, allows costs and final application size reduction. In this scenario scientific community and industries are very active to drive innovation.
标签: Magnetometers Lorentz Force MEMS
上传时间: 2020-06-06
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In the present era, low observability is one of the critical requirements in aerospace sector, especially related to defense. The stealth technology essentially relates to shaping and usage of radar absorbing materials (RAM) or radar absorbing struc- tures (RAS). The performance of such radar cross section (RCS) reduction tech- niques is limited by the bandwidth constraints, payload requirements, and other structural issues. Moreover, with advancement of materials science, the structure geometry no longer remains key decisive factor toward stealth.
标签: Fundamentals Design Radar of EM
上传时间: 2020-06-06
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Power Electronics is one of modern and key technologies in Electrical and Electronics Engineering for green power, sustainable energy systems, and smart grids. Especially, the transformation of existing electric power systems into smart grids is currently a global trend. The gradual increase of distributed generators in smart grids indicates a wide and important role for power electronic converters in the electric power system, also with the increased use of power electronics devices (nonlinear loads) and motor loadings, low cost, low-loss and high-performance shunt current quality compensators are highly demanded by power customers to solve current quality problems caused by those loadings.
标签: Electronics Parallel Filters Power
上传时间: 2020-06-07
上传用户:shancjb