Ultra-wideband (UWB) technology enables high data-rate short-range communica- tion, in excess of hundredmegabit-per-secondsand up to multi-gigabit-per-seconds, over a wide spectrum of frequencies, while keeping power consumption at low lev- els. This low power operation results in a less-interfering co-existence with other existed communication technologies (e.g., UNII bands). In addition to carrying a huge amount of data over a distance of up to 230 feet at very low power (less than 0.5mW), the UWB signal has the ability to penetrate through the doors and other obstacles that tend to reflect signals at more limited bandwidths and higher power densities.
標(biāo)簽: Silicon-Based Front-Ends RF
上傳時(shí)間: 2020-06-01
上傳用戶:shancjb
Software Radio (SR) is one of the most important emerging technologies for the future of wireless communication services. By moving radio functionality into software, it promises to give flexible radio systems that are multi-service, multi- standard, multi-band, reconfigurable and reprogrammable by software. Today’s radios are matched to a particular class of signals that are well defined bytheircarrierfrequencies,modulationformatsandbandwidths.Aradiotransmitter today can only up convert signals with well-defined bandwidths over defined center frequencies, while, on the other side of the communication chain, a radio receiver can only down convert well-defined signal bandwidths, transmitted over specified carrier frequencies.
上傳時(shí)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(biāo)簽: Telecommunications Modeling
上傳時(shí)間: 2020-06-01
上傳用戶:shancjb
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.”
標(biāo)簽: Time-Varying Channels
上傳時(shí)間: 2020-06-01
上傳用戶:shancjb
During the past three decades, the world has seen signifi cant changes in the telecom- munications industry. There has been rapid growth in wireless communications, as seen by large expansion in mobile systems. Wireless communications have moved from fi rst-generation (1G) systems primarily focused on voice communications to third-generation (3G) systems dealing with Internet connectivity and multi-media applications. The fourth-generation (4G) systems will be designed to connect wire- less personal area networks (WPANs), wireless local area networks (WLANs) and wireless wide-area networks (WWANs).
標(biāo)簽: Communications Networking Wireless
上傳時(shí)間: 2020-06-01
上傳用戶:shancjb
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.
標(biāo)簽: Communication Wireless Circuits Systems and
上傳時(shí)間: 2020-06-01
上傳用戶:shancjb
The explosion in demand for wireless services experienced over the past 20 years has put significant pressure on system designers to increase the capacity of the systems being deployed. While the spectral resource is very scarce and practically exhausted, the biggest possibilities are predicted to be in the areas of spectral reuse by unlicensed users or in exploiting the spatial dimension of the wireless channels. The former approach is now under intense development and is known as the cogni- tive radio approach (Haykin 2005).
標(biāo)簽: Multi-Antenna Wireless Channels Modeling
上傳時(shí)間: 2020-06-01
上傳用戶:shancjb
The planarization technology of Chemical-Mechanical-Polishing (CMP), used for the manufacturing of multi- level metal interconnects for high-density Integrated Circuits (IC), is also readily adaptable as an enabling technology in MicroElectroMechanical Systems (MEMS) fabrication, particularly polysilicon surface micromachining. CMP not only eases the design and manufacturability of MEMS devices by eliminating several photolithographic and film issues generated by severe topography, but also enables far greater flexibility with process complexity and associated designs. T
標(biāo)簽: mechanical polishing Chemical
上傳時(shí)間: 2020-06-06
上傳用戶:shancjb
stract With global drivers such as better energy consumption, energy efficiency and reduction of greenhouse gases, CO 2 emission reduction has become key in every layer of the value chain. Power Electronics has definitely a role to play in these thrilling challenges. From converters down to compound semiconductors, innovation is leading to breakthrough technologies. Wide BandGap, Power Module Packaging, growth of Electric Vehicle market will game change the overall power electronic industry and supply chain. In this presentation we will review power electronics trends, from technologies to markets.
標(biāo)簽: Electronics Materials Power WBG for
上傳時(shí)間: 2020-06-07
上傳用戶:shancjb
adio Frequency Identification (RFID) is a rapidly developing automatic wireless data-collection technology with a long history.The first multi-bit functional passive RFID systems,with a range of several meters, appeared in the early 1970s, and continued to evolve through the 1980s. Recently, RFID has experienced a tremendous growth,due to developments in integrated circuits and radios, and due to increased interest from the retail industrial and government.
標(biāo)簽: RFID-Enabled Sensors RFID and
上傳時(shí)間: 2020-06-08
上傳用戶:shancjb
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