Download or read book Performance Evaluation of a Cyclic prefix Free OFDM System in Accordance with the IEEE 802 11a Standard written by Jyothirmayee Nulu and published by . This book was released on 2004 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cyclic Prefix in Ofdm Systems written by Zhiqiang Chen and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Cyclic Prefix in OFDM Systems" by Zhiqiang, Chen, 陳志強, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled "Cyclic Prefix in OFDM systems" Submitted by Chen ZhiQiang for the degree of Doctor of Philosophy at The University of Hong Kong in July 2007 Orthogonal frequency division multiplexing (OFDM) is an efficient multiplexing technology in wireless communications. A guard time, usually in the form of cyclic prefix (CP), is inserted between OFDM symbols to eliminate both the inter-symbol interference (ISI) and the inter-channel interference (ICI). The traditional "one size fits all" CP insertion method sets the CP length longer than the channel maximum excess delay. In contrast, one novel CP insertion method is proposed in this thesis which not only depends on the channel delay profile but also the signal-to-noise ratio (SNR). The numerical results show that the newly proposed CP length outperforms the traditional length in both bandwidth efficiency and power efficiency. Because the insertion of CP requires additional bandwidth to accommodate the redundancy, many algorithms have been proposed to decrease the CP length at the expense of the transceiver's complexity. The novel method of CP insertion, however, proposes to decrease the CP length without any increase in complexity. The scheme without CP insertion is also proposed for the system working at low SNR regime. Numerical results show that in such a system the scheme without CP insertion yields a significant bandwidth efficiency increase with a penalty of a trivial power efficiency decrease. While hybrid OFDM systems, which are the combinations of OFDM and other technologies such as code division multiple access (CDMA) and multiple-input multiple- output (MIMO) have been the subject of considerable research, the CP insertions in these systems have not been studied sufficiently. These issues are therefore intensively investigated in this thesis. Firstly, the CP insertion in the point-to-point multi-carrier CDMA (MC CDMA) system, which is the major form of the combination of OFDM and CDMA, is examined. The simulation results show that the optimum CP length decreases with the increase of the spreading gain. Secondly, for the MC CDMA cellular system, a novel CP insertion method based on maximizing the system effective data rate is proposed. It is concluded from the analytical numerical results that the insertion of CP has achieved no benefit and can be discarded. Thirdly, the pairwise error probability (PEP) performance is analyzed and derived for the space time coding OFDM (STC- OFDM) system with insufficient CP. Particularly, the bit error rate (BER) performance is derived for the Alamouti coding OFDM (Alamouti-OFDM) system. Both the analytical numerical results and the Monte Carlo simulation results show that the optimum CP length decreases as the number of receive antennae increases. Finally, the frame error rate (FER) performance is evaluated for the single-input multiple-output OFDM (SIMO- OFDM) system and MIMO-OFDM system. The simulation results reveal that the insertion of CP can be abandoned while the number of receive antennae is large. In all these situations the schemes without CP insertion require no increase in complexity. DOI: 10.5353/th_b3955833 Subjects: Interference (Sound) Orthogonal frequency division multiplexing

Download or read book OFDM System Cyclic Prefix Characteristic Analysis for WIMAX Technology written by Adeb Ali Mohammed Ahmed and published by . This book was released on 2015 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The IEEE International Symposium on Personal Indoor and Mobile Radio Communications written by IEEE International Symposium on Personal, Indoor, and Mobile Radio Communications and published by . This book was released on 1995 with total page 824 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Block Turbo Code and Its Application to OFDM for Wireless Local Area Network written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: To overcome multipath fading and Inter symbol Interference (ISI), in convolutional single carrier systems equalizers are used. But it increases the system complexity. Another approach is to use a multicarrier modulation technique such as OFDM, where the data stream to be transmitted is divided into several lower rate data streams each being modulated on a subcarrier. To avoid ISI, a small interval, known as the guard time interval, is inserted into OFDM symbols. The length of the guard time interval is chosen to exceed the channel delay spread. Therefore, OFDM can combat the multipath fading and eliminate ISI almost completely. The another problem is the reduction of the error rate in transmitting digital data. For that we use error correcting Codes in the design of digital transmission systems. Turbo Codes have been widely considered to be the most powerful error control code of practical importance. Turbo codes can be achieved by serial or parallel concatenation of two (or more) codes called the constituent codes. The constituent codes can be either block codes or convolutional codes. Currently, most of the work on turbo codes have essentially focused on Convolutional Turbo Code (CTC)s and Block Turbo Code (BTC)s have been partially neglected. Yet, the BTC solution is more attractive for a wide range of applications. In this paper, Block Turbo Codes or Turbo Product Codes are used which is similar to the IEEE 802.11a WLAN standard. In this thesis work simple explanation of BTCOFDM theory is given. The BER performance is evaluated for the Block Turbo coded BPSK and QPSK OFDM system, under both AWGN channel and Rayleigh fading channel. It also compares the BER performance of Block Turbo coded OFDM with the uncoded OFDM. It is verified in the present work that the BTCOFDM system with 4 iterations is sufficient to provide a good BER performance. Additional number of iterations does not show noticeable difference. The simulation results shows that the BTCOFDM system ac.

Download or read book Proceedings written by and published by . This book was released on 2003 with total page 1232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cyclic Prefix in OFDM Systems written by Zhiqiang Chen (Electronic engineer.) and published by . This book was released on 2007 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Adaptive Channel Estimation of OFDM Systems Using the Cyclic Prefix with an RLS Based Algorithm in Mobile Channels written by Ziya Dereboylu and published by . This book was released on 2005 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Conference Proceedings written by and published by . This book was released on 2004 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Broadband Wireless Access and Local Networks written by Byeong Gi Lee and published by Artech House. This book was released on 2008 with total page 647 pages. Available in PDF, EPUB and Kindle. Book excerpt: This authoritative resource offers you complete, state-of-the-art coverage of wireless broadband access networks. The book provides you with a thorough introduction to wireless access and local networks, covers broadband mobile wireless access systems, and details mobile and broadband wireless local area networks. This forward-looking reference focuses on cutting-edge mobile WiMax, WiFi, and WiBro technologies, including in-depth design and implementation guidance. Collecting the most recent experience and knowledge of design and field engineers from leading organizations like Samsung Electronics, Korea Telecom (KT) Corporation and Philips Electronics, the book introduces the network technologies adopted by Mobile WiMAX for the implementation of IP-based broadband mobile wireless access. Moreover, it covers the Wi-Fi technologies that have steadily evolved over the past decade, establishing a firm foundation for IP-based wireless local network access.

Download or read book OFDM Systems for Wireless Communications written by Adarsh Narasimhamurthy and published by Springer Nature. This book was released on 2022-06-01 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal Frequency Division Multiplexing (OFDM) systems are widely used in the standards for digital audio/video broadcasting, WiFi and WiMax. Being a frequency-domain approach to communications, OFDM has important advantages in dealing with the frequency-selective nature of high data rate wireless communication channels. As the needs for operating with higher data rates become more pressing, OFDM systems have emerged as an effective physical-layer solution. This short monograph is intended as a tutorial which highlights the deleterious aspects of the wireless channel and presents why OFDM is a good choice as a modulation that can transmit at high data rates. The system-level approach we shall pursue will also point out the disadvantages of OFDM systems especially in the context of peak to average ratio, and carrier frequency synchronization. Finally, simulation of OFDM systems will be given due prominence. Simple MATLAB programs are provided for bit error rate simulation using a discrete-time OFDM representation. Software is also provided to simulate the effects of inter-block-interference, inter-carrier-interference and signal clipping on the error rate performance. Different components of the OFDM system are described, and detailed implementation notes are provided for the programs. The program can be downloaded here. Table of Contents: Introduction / Modeling Wireless Channels / Baseband OFDM System / Carrier Frequency Offset / Peak to Average Power Ratio / Simulation of the Performance of OFDM Systems / Conclusions

Download or read book Bandwidth Efficient Digital Modulation with Application to Deep Space Communications written by Marvin K. Simon and published by John Wiley & Sons. This book was released on 2005-03-04 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important look at bandwidth-efficient modulations with applications to today's Space program Based on research and results obtained at the California Institute of Technology's Jet Propulsion Laboratory, this timely book defines, describes, and then delineates the performance (power and bandwidth) of digital communication systems that incorporate a wide variety of bandwidth-efficient modulations appropriate for the design and implementation of space communications systems. The author compares the performance of these systems in the presence of a number of practical (non-ideal) transmitter and receiver characteristics such as modulator and phase imbalance, imperfect carrier synchronization, and transmitter nonlinearity. Although the material focuses on the deep space applications developed at the Jet Propulsion Laboratory, the presentation is sufficiently broad as to be applicable to a host of other applications dealing with RF communications. An important contribution to the scientific literature, Bandwidth-Efficient Digital Modulation with Application to Deep Space Communications * was commissioned by the JPL Deep Space Communications and Navigation System Center of Excellence * highlights many NASA-funded technical contributions pertaining to deep space communications systems * is a part of the prestigious Deep Space Communications and Navigation Series The Deep Space Communications and Navigation Series is authored by scientists and engineers with extensive experience in astronautics, communications, and related fields. It lays the foundation for innovation in the areas of deep space navigation and communications by disseminating state-of-the-art knowledge in key technologies.

Download or read book Fundamentals of Wireless Communication written by David Tse and published by Cambridge University Press. This book was released on 2005-05-26 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook takes a unified view of the fundamentals of wireless communication and explains cutting-edge concepts in a simple and intuitive way. An abundant supply of exercises make it ideal for graduate courses in electrical and computer engineering and it will also be of great interest to practising engineers.

Download or read book MIMO OFDM Wireless Communications with MATLAB written by Yong Soo Cho and published by John Wiley & Sons. This book was released on 2010-08-20 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: MIMO-OFDM is a key technology for next-generation cellular communications (3GPP-LTE, Mobile WiMAX, IMT-Advanced) as well as wireless LAN (IEEE 802.11a, IEEE 802.11n), wireless PAN (MB-OFDM), and broadcasting (DAB, DVB, DMB). In MIMO-OFDM Wireless Communications with MATLAB®, the authors provide a comprehensive introduction to the theory and practice of wireless channel modeling, OFDM, and MIMO, using MATLAB® programs to simulate the various techniques on MIMO-OFDM systems. One of the only books in the area dedicated to explaining simulation aspects Covers implementation to help cement the key concepts Uses materials that have been classroom-tested in numerous universities Provides the analytic solutions and practical examples with downloadable MATLAB® codes Simulation examples based on actual industry and research projects Presentation slides with key equations and figures for instructor use MIMO-OFDM Wireless Communications with MATLAB® is a key text for graduate students in wireless communications. Professionals and technicians in wireless communication fields, graduate students in signal processing, as well as senior undergraduates majoring in wireless communications will find this book a practical introduction to the MIMO-OFDM techniques. Instructor materials and MATLAB® code examples available for download at www.wiley.com/go/chomimo

Download or read book LTE for 4G Mobile Broadband written by Farooq Khan and published by Cambridge University Press. This book was released on 2009-03-26 with total page 507 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understand the new technologies of the LTE standard and their impact on system performance improvements with this practical guide.

Download or read book OFDM for Optical Communications written by William Shieh and published by Academic Press. This book was released on 2009-09-18 with total page 457 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first book on optical OFDM by the leading pioneers in the field The only book to cover error correction codes for optical OFDM Gives applications of OFDM to free-space communications, optical access networks, and metro and log haul transports show optical OFDM can be implemented Contains introductions to signal processing for optical engineers and optical communication fundamentals for wireless engineers This book gives a coherent and comprehensive introduction to the fundamentals of OFDM signal processing, with a distinctive focus on its broad range of applications. It evaluates the architecture, design and performance of a number of OFDM variations, discusses coded OFDM, and gives a detailed study of error correction codes for access networks, 100 Gb/s Ethernet and future optical networks. The emerging applications of optical OFDM, including single-mode fiber transmission, multimode fiber transmission, free space optical systems, and optical access networks are examined, with particular attention paid to passive optical networks, radio-over-fiber, WiMAX and UWB communications. Written by two of the leading contributors to the field, this book will be a unique reference for optical communications engineers and scientists. Students, technical managers and telecom executives seeking to understand this new technology for future-generation optical networks will find the book invaluable. William Shieh is an associate professor and reader in the electrical and electronic engineering department, The University of Melbourne, Australia. He received his M.S. degree in electrical engineering and Ph.D. degree in physics both from University of Southern California. Ivan Djordjevic is an Assistant Professor of Electrical and Computer Engineering at the University of Arizona, Tucson, where he directs the Optical Communications Systems Laboratory (OCSL). His current research interests include optical networks, error control coding, constrained coding, coded modulation, turbo equalization, OFDM applications, and quantum error correction. "This wonderful book is the first one to address the rapidly emerging optical OFDM field. Written by two leading researchers in the field, the book is structured to comprehensively cover any optical OFDM aspect one could possibly think of, from the most fundamental to the most specialized. The book adopts a coherent line of presentation, while striking a thoughtful balance between the various topics, gradually developing the optical-physics and communication-theoretic concepts required for deep comprehension of the topic, eventually treating the multiple optical OFDM methods, variations and applications. In my view this book will remain relevant for many years to come, and will be increasingly accessed by graduate students, accomplished researchers as well as telecommunication engineers and managers keen to attain a perspective on the emerging role of OFDM in the evolution of photonic networks." -- Prof. Moshe Nazarathy, EE Dept., Technion, Israel Institute of Technology The first book on optical OFDM by the leading pioneers in the field The only book to cover error correction codes for optical OFDM Applications of OFDM to free-space communications, optical access networks, and metro and log haul transports show optical OFDM can be implemented An introduction to signal processing for optical communications An introduction to optical communication fundamentals for the wireless engineer

Download or read book OFDM and MC CDMA written by Lajos Hanzo and published by John Wiley & Sons. This book was released on 2007-01-11 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless communications has witnessed a tremendous growth during the past decade and further spectacular enabling technology advances are expected in an effort to render ubiquitous wireless connectivity a reality. Currently, a technical in-depth book on this subject is unavailable, which has a similar detailed exposure of OFDM, MIMO-OFDM and MC-CDMA. A further attraction of the joint treatment of these topics is that it allows the reader to view their design trade-offs in a comparative context. Divided into three main parts: Part I provides a detailed exposure of OFDM designed for employment in various applications Part II is another design alternative applicable in the context of OFDM systems where the channel quality fluctuations observed are averaged out with the aid of frequency-domain spreading codes, which leads to the concept of MC-CDMA Part III discusses how to employ multiple antennas at the base station for the sake of supporting multiple users in the uplink By providing an all-encompassing self-contained treatment this volume will appeal to a wide readership, as it is both an easy-reading textbook and a high-level research monograph.