Before delving into the details of orthogonal frequency division multiplexing (OFDM), relevant background material must be presented first. The purpose of this chapter is to provide the necessary building blocks for the development of OFDM principles. Included in this chapter are reviews of stochastic and random process, discrete-time signals and systems, and the Discrete Fourier Transform (DFT). Tooled with the necessary mathematical foundation, we proceed with an overview of digital communication systems and OFDM communication systems. We conclude the chapter with summaries of the OFDM wireless LAN standards currently in existence and a high-level comparison of single carrier systems versus OFDM.
上传时间： 2020-05-31
上传用户：shancjb
Emerging technologies such as WiFi and WiMAX are profoundly changing the landscape of wireless broadband. As we evolve into future generation wireless networks, a primary challenge is the support of high data rate, integrated multi- media type traffic over a unified platform. Due to its inherent advantages in high-speed communication, orthogonal frequency division multiplexing (OFDM) has become the modem of choice for a number of high profile wireless systems (e.g., DVB-T, WiFi, WiMAX, Ultra-wideband).
标签： OFDM-Based Broadband Networks Wireless
上传时间： 2020-05-31
上传用户：shancjb
Orthogonal frequency division multiplexing (OFDM) has been shown to be an effective technique to combat multipath fading in wireless channels. It has been and is going to be used in various wireless communication systems. This book gives a comprehensive introduction on the theory and practice of OFDM for wireless communications.
标签： Multiplexing Orthogonal Frequency Division
上传时间： 2020-05-31
上传用户：shancjb
Radio frequency spectrum is a scarce and critical natural resource that is utilized for many services including surveillance, navigation, communication, and broadcast- ing. Recent years have seen tremendous growth in the use of spectrum especially by commercial cellular operators. Ubiquitous use of smartphones and tablets is one of the reasons behind an all-time high utilization of spectrum. As a result, cellular operators are experiencing a shortage of radio spectrum to meet bandwidth demands of users. On the other hand, spectrum measurements have shown that much spectrum not held by cellular operators is underutilized even in dense urban areas. This has motivated shared access to spectrum by secondary systems with no or minimal impact on incumbent systems. Spectrum sharing is a promising approach to solve the problem of spectrum congestion as it allows cellular operators access to more spectrum in order to satisfy the ever-growing bandwidth demands of commercial users.
标签： Spectrum Sharing Between Radars
上传时间： 2020-06-01
上传用户：shancjb
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
上传时间： 2020-06-01
上传用户：shancjb
The advent of modern wireless devices, such as smart phones and MID 1 terminals, has revolutionized the way people think of personal connectivity. Such devices encompass multiple applications ranging from voice and video to high-speed data transfer via wireless networks. The voracious appetite of twenty-first century users for supporting more wireless applications on a single device is ever increasing. These devices employ multiple radios and modems that cover multiple frequency bands and multiple standards with a manifold of wireless applications often running simultaneously.
标签： Architectures Wireless Receiver Design and
上传时间： 2020-06-01
上传用户：shancjb
The first edition as well as its forerunner of Kuffel and Abdullah published in 1970 and their translations into Japanese and Chinese languages have enjoyed wide international acceptance as basic textbooks in teaching senior under- graduate and postgraduate courses in High-Voltage Engineering. Both texts have also been extensively used by practising engineers engaged in the design and operation of high-voltage equipment. Over the years the authors have received numerous comments from the text’s users with helpful suggestions for improvements. These have been incorporated in the present edition. Major revisions and expansion of several chapters have been made to update the continued progress and developments in high-voltage engineering over the past two decades.
标签： Engineering Voltage High
上传时间： 2020-06-07
上传用户：shancjb
There is an unprecedented enthusiasm for radio frequency identification (RFID) technologies today. RFID is based on the exchange of information carried by electromagnetic waves between a label, or tag, and a reader. This technology is currently in full economic expansion, which has manifested itself in widely backed research activities, some of which will be examined in this book.
标签： Identification Frequency Sensors Radio and
上传时间： 2020-06-08
上传用户：shancjb
Radio frequency identification (RFID) is a type of automatic identification systems which has gained popularity in recent years for being fast and reliable in keeping track of the individual objects. In RFID systems, contactless object identification is achieved using radio signals without the need for physical contact as the case with other existing identification technologies such as barcodes. Therefore, a huge number of items can be identified in a short amount of time with high reliability and low cost which makes the RFID technology very attractive for a wide range of applications such as supply chain management, e-health, monitoring humans, pets, animals, and many other objects, toll control, and electrical tagging. Furthermore, RFID technology eliminates the human error and reduces the total cost of the products.
上传时间： 2020-06-08
上传用户：shancjb
Multisim官方示例Multisim仿真例程基础电路范例135例合集:Chapter 1 - RLC CircuitsChapter 2 - DiodesChapter 3 - TransistorsChapter 4 - AmplifiersChapter 5 - OpampsChapter 6 - FiltersChapter 7 - Miscellaneous CircuitsFundamental Circuits.pdf004 Parallel DC Circuits.ms10005 Series-Parrallel DC Circuit.ms10006 Current Analysis.ms10007 Millmans Theorem 1.ms10008 Millmans Theorem 2.ms10009 Kirchhoff's Current Law.ms10010 Thevenin's Theorem.ms10011 Superposition Principle.ms10012 Nortons Theorem and Source Conversion.ms10013 AC Voltage Measurement.ms10014 Frequency Response of the Series RL Network.ms10015 RL High and Low Pass Filter.ms10016 Frequency Response of the Series RC Network.ms10017 RC High and Low Pass Filter.ms10019 Center-Tapped Full-Wave Rectifier.ms10020 Bridge Rectifier.ms10021 Capacitor-Input Rectifier Filter.ms10022 Diode Clipper (Limiter).ms10023 Diode Clipper.ms10024 Diode Clamper (DC Restorer).ms10025 Diode Voltage Doubler.ms10026 Zener Diode and Voltage Regulation 1.ms10027 Zener Diode and Voltage Regulation 2.ms10028 Zener Diode and Voltage Regulation 3.ms10105 TTL Inverter.ms10107 TTL Gate.ms10109 OR Gate Circuit.ms10111 Over-Damp Circuit.ms10113 Critical-Damp Circuit.ms10115 Series RLC Circuit 1.ms10117 Clapp Oscillator.ms10119 Differential Amplifier 1.ms10121 Differential Amplifier in Common Mode.ms10123 LC Oscillator with Unity Gain Buffer.ms10125 Notch Filter.ms10127 PNP Differential Pair.ms10129 Crossover Network.ms10131 Second-Order High-Pass Chebyshev Filter.ms10133 Third-Order High-Pass Chebyshev Filter.ms10135 Fifth-Order High-Pass Filter.ms10
标签： multisim
上传时间： 2021-10-27
上传用户：trh505
