Download or read book Hybrid Automatic Repeat Request Schemes Using Turbo Codes and Low density Parity Check Codes written by Ramesh Mantha and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hybrid automatic repeat request (HARQ) techniques based on turbo codes and low density parity check (LDPC) codes are presented. These codes are the most powerful known error control codes and open up the possibility of approaching channel capacity with HARQ systems. The implemented HARQ systems use a technique based on puncturing the parity bits of a low rate turbo or LDPC code. Some of these punctured bits are then transmitted after each retransmission request. Simulation results show throughput performances within 1.5 dB of channel capacity in AWGN channels and within 1.5 dB of channel capacity in fully interleaved Rayleigh fading channels.

Download or read book Turbo Coded Hybrid Automatic Repeat Request and Differential Space time Spreading written by Tao Shi and published by . This book was released on 2007 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In this dissertation, we focus our work on some transmission technologies for the protection of data against wireless hostile channels. Segment selective repeat (SSR) is first proposed as an effective retransmission strategy for improving the transmission efficiency in turbo coded hybrid automatic repeat request (TC-HARQ) systems. The received data frame is estimated for error corruption status with soft information from turbo codes. Only the more severely corrupted portions of a frame are retransmitted upon error. SSR-based TC-HARQ strategy achieves higher throughput with similar bit error rate (BER) as compared to some traditional approaches. Performance bounds are also developed for TC-HARQ based on transfer function bounds on turbo codes. The proposed bounds match closely with the simulation results at high signal to noise ratio (SNR) regions. Considering the application of space-time spreading (STS) without channel state information, we then propose differential detection of space-time spreading (DDSTS) and differential space-time spreading (DSTS). Diversity gains can still be achieved from multiple transmit and receive antennas, and from multipath fading channel with the employment of Rake receiver structure. The proposed schemes provide alternatives of employing STS in environments where perfect channel estimation is not available or is a high cost. Finally we study a combined design of SSR-based automatic repeat request (ARQ) with DSTS, where the estimated channel gain from DSTS is utilized by SSR-based ARQ to determine the quality of segments and make the retransmission for some worse segments accordingly. The performance of the scheme is better than schemes that either make retransmission of an entire frame or some random segments.

Download or read book Conference Record written by and published by . This book was released on 1999 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Turbo like Coding for Spread spectrum Communications written by Hasung Kim and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis studies advanced error control schemes using turbo-like codes, turbo-like coded modulations, turbo hybrid-ARQ (Automatic Repeat reQuest) schemes, and rate compatible puncturing techniques for reliable and adaptive commercial and tactical spread-spectrum communications, especially for code-division multiple access (CDMA) cellular systems and direct-sequence (DS) and frequency-hopping (FH) anti-jam systems. Furthermore, we utilize both the maximum-likelihood (ML) bounding techniques and convergence analysis to design and analyze various turbo-like coding schemes that show different behaviors in error performance from conventional trellis coding schemes. In the area of DS-CPM, we propose a DS concatenated coded CPM system for pulse-noise jamming channels and an anti-jam iterative receiver utilizing jammer state information. We also design a mixed concatenated CPM system that mixes CPM schemes with different convergence characteristics. In addition, we present the ML bound and convergence analysis for the jamming channel. In the area of FH-CPM, we propose anti-jam serially concatenated slow FH-CPM systems, whose phase is continuous during each hop interval, along with coherent and non-coherent iterative receivers. We also propose an iterative jamming estimation technique for the iterative receiver. In the area of multi-h CPM, we propose a power- and bandwidth-efficient serially concatenated multi-h CPM along with an appropriate iterative receiver structure. Serially concatenated multi-h CPM is shown to outperform single-h CPM. To design adaptive and versatile error control schemes using turbo-like codes for packet-data networks, we propose turbo hybrid-ARQ (HARQ) and rate compatible puncturing techniques for retransmission. In the area of turbo hybrid-ARQ, we propose a Type-I turbo HARQ scheme using a concatenated RS-turbo code and a packet combining technique for W-CDMA system to improve the performance of error and decoding latency. The W-CDMA system including the fast power control and coherent Rake receiver with a channel estimation technique for multipath fading channels is considered. Finally, in the area of rate compatible punctured turbo-like codes, we propose rate compatible punctured turbo (RCPT) codes and rate compatible punctured serially concatenated convolutional (RCPS) codes along with their puncturing methods. In addition, we propose Type-II RCPT-HARQ and RCPS-HARQ schemes to perform an efficient incremental redundancy retransmission.

Download or read book Cellular Communication Networks and Standards written by Wei Jiang and published by Springer Nature. This book was released on with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Mobile Broadcasting written by Borko Furht and published by CRC Press. This book was released on 2008-04-15 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt: Operators are introducing mobile television and digital video content services globally. The Handbook of Mobile Broadcasting addresses all aspects of these services, providing a comprehensive reference on DVB-H, DMB, ISDB-T, and MediaFLO. Featuring contributions from experts in the field, the text presents technical standards and distribution proto

Download or read book ADVD TECHNIQUES FOR HIGH SPEED written by Yiqing Zhou and published by Open Dissertation Press. This book was released on 2017-01-27 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Advanced Techniques for High Speed Wireless Communications" by Yiqing, Zhou, 周一靑, 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 "Advanced Techniques for High Speed Wireless Communications" Submitted by Zhou Yiqing for the degree of Doctor of Philosophy at The University of Hong Kong in November 2003 Future wireless communication systems aim to provide extremely high speed data transmission. To improve the data rate in wireless communications, some advanced techniques are investigated in this thesis, including turbo-coded hybrid automatic-repeat-request (ARQ), variable-spreading-factor (VSF) orthogonal frequency and code division multiplexing (OFCDM) systems, and hybrid multi-code interference (MCI) cancellation and minimum mean square error (MMSE) detection. Turbo codes have been proposed in ARQ systems as the forward-error-correction (FEC) codes. Although sub-packet schemes have been proposed in ARQ systems, optimum sub-packet transmission is more effective to maximize throughput in a dynamic channel. Chapter 2 shows that turbo codes illustrate sparse and burst packet error patterns at moderate to high signal-to-noise ratio (SNR). These patterns are suitable for sub-packet schemes. Moreover, sub-packet schemes can provide additional error correction capability with iterative turbo decoding algorithms. An efficient method is proposed to estimate the optimum number of sub-packets, and adaptive sub-packet schemes (i.e. schemes that enable a system to employ different optimum numbers of sub-packets under variable conditions) are suggested to achieve the maximum throughput of the system. Simulations show that the adaptive sub-packet scheme is effective at moderate SNR (e.g. from 2.6dB to 5.0dB) and can provide higher throughput, reduced delay, and lower dropping rate than conventional packet schemes. The broadband VSF-OFCDM system with two-dimensional spreading (time and frequency domain spreading) is becoming a very attractive technique for high speed wireless communications. Assuming slow fading and ideal channel estimation, an analytical study is presented in Chapter 3 on the performance of the VSF-OFCDM system with hybrid MCI cancellation and MMSE detection. The weights of MMSE are derived and updated stage by stage of MCI cancellation. Defining N=NN TF as the total spreading factor, where N and N are the spreading factors in time and T F frequency domain respectively, various values of N and N are dealt with in a T F quadrature-phase-shift-keying(QPSK)-modulated VSF-OFCDM system. It is shown that the hybrid detection scheme performs much better than the pure MMSE. For the hybrid detection, a larger value of N is expected. With hybrid detection, the performance of VSF-OFCDM systems over a fast fading channel is analytically studied in Chapter 4. It is shown that in a fast fading channel, considerable improvement in bit-error-rate (BER) can be achieved by use of a novel code assignment approach. The optimum power ratio of pilot channel to one data channel is about 0.25K, where K is the total number of data channels. When the Doppler frequency f is less than 200Hz, the effect of the Doppler on the system performance is negligible. However, increasing f from 200Hz degrades the system performance rapidly. Although the gap in BER between the hybrid and pure MMSE detection decreases as f increases, the gap is still large as long as f is less than D D around 800Hz. For a wide range of Doppler shift, a larger N is expected, whereas a smaller N provides better performance w

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2005 with total page 794 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The 13th IEEE International Symposium on Personal Indoor and Mobile Radio Communications written by and published by . This book was released on 2002 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings written by and published by . This book was released on 2002 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Turbo Code Applications written by Keattisak Sripimanwat and published by Springer Science & Business Media. This book was released on 2005-10-07 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbo Code Applications: a journey from a paper to realization presents c- temporary applications of turbo codes in thirteen technical chapters. Each chapter focuses on a particular communication technology utilizing turbo codes, and they are written by experts who have been working in related th areas from around the world. This book is published to celebrate the 10 year anniversary of turbo codes invention by Claude Berrou Alain Glavieux and Punya Thitimajshima (1993-2003). As known for more than a decade, turbo code is the astonishing error control coding scheme which its perf- mance closes to the Shannon’s limit. It has been honored consequently as one of the seventeen great innovations during the ?rst ?fty years of information theory foundation. With the amazing performance compared to that of other existing codes, turbo codes have been adopted into many communication s- tems and incorporated with various modern industrial standards. Numerous research works have been reported from universities and advance companies worldwide. Evidently, it has successfully revolutionized the digital commu- cations. Turbo code and its successors have been applied in most communications startingfromthegroundorterrestrialsystemsofdatastorage,ADSLmodem, and ?ber optic communications. Subsequently, it moves up to the air channel applications by employing to wireless communication systems, and then ?ies up to the space by using in digital video broadcasting and satellite com- nications. Undoubtedly, with the excellent error correction potential, it has been selected to support data transmission in space exploring system as well.

Download or read book Error Control Coding written by Lin Shu and published by Pearson Education India. This book was released on 2011 with total page 1276 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Understanding LTE with MATLAB written by Houman Zarrinkoub and published by John Wiley & Sons. This book was released on 2014-01-28 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: An introduction to technical details related to the Physical Layer of the LTE standard with MATLAB® The LTE (Long Term Evolution) and LTE-Advanced are among the latest mobile communications standards, designed to realize the dream of a truly global, fast, all-IP-based, secure broadband mobile access technology. This book examines the Physical Layer (PHY) of the LTE standards by incorporating three conceptual elements: an overview of the theory behind key enabling technologies; a concise discussion regarding standard specifications; and the MATLAB® algorithms needed to simulate the standard. The use of MATLAB®, a widely used technical computing language, is one of the distinguishing features of this book. Through a series of MATLAB® programs, the author explores each of the enabling technologies, pedagogically synthesizes an LTE PHY system model, and evaluates system performance at each stage. Following this step-by-step process, readers will achieve deeper understanding of LTE concepts and specifications through simulations. Key Features: • Accessible, intuitive, and progressive; one of the few books to focus primarily on the modeling, simulation, and implementation of the LTE PHY standard • Includes case studies and testbenches in MATLAB®, which build knowledge gradually and incrementally until a functional specification for the LTE PHY is attained • Accompanying Web site includes all MATLAB® programs, together with PowerPoint slides and other illustrative examples Dr Houman Zarrinkoub has served as a development manager and now as a senior product manager with MathWorks, based in Massachusetts, USA. Within his 12 years at MathWorks, he has been responsible for multiple signal processing and communications software tools. Prior to MathWorks, he was a research scientist in the Wireless Group at Nortel Networks, where he contributed to multiple standardization projects for 3G mobile technologies. He has been awarded multiple patents on topics related to computer simulations. He holds a BSc degree in Electrical Engineering from McGill University and MSc and PhD degrees in Telecommunications from the Institut Nationale de la Recherche Scientifique, in Canada. www.wiley.com/go/zarrinkoub

Download or read book Modulation and Coding Techniques in Wireless Communications written by Evgenii Krouk and published by John Wiley & Sons. This book was released on 2011-02-21 with total page 691 pages. Available in PDF, EPUB and Kindle. Book excerpt: The high level of technical detail included in standards specifications can make it difficult to find the correlation between the standard specifications and the theoretical results. This book aims to cover both of these elements to give accessible information and support to readers. It explains the current and future trends on communication theory and shows how these developments are implemented in contemporary wireless communication standards. Examining modulation, coding and multiple access techniques, the book is divided into two major sections to cover these functions. The two-stage approach first treats the basics of modulation and coding theory before highlighting how these concepts are defined and implemented in modern wireless communication systems. Part 1 is devoted to the presentation of main L1 procedures and methods including modulation, coding, channel equalization and multiple access techniques. In Part 2, the uses of these procedures and methods in the wide range of wireless communication standards including WLAN, WiMax, WCDMA, HSPA, LTE and cdma2000 are considered. An essential study of the implementation of modulation and coding techniques in modern standards of wireless communication Bridges the gap between the modulation coding theory and the wireless communications standards material Divided into two parts to systematically tackle the topic - the first part develops techniques which are then applied and tailored to real world systems in the second part Covers special aspects of coding theory and how these can be effectively applied to improve the performance of wireless communications systems

Download or read book Turbo Coding Turbo Equalisation and Space Time Coding written by Lajos Hanzo and published by John Wiley & Sons. This book was released on 2011-05-03 with total page 839 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering the full range of channel codes from the most conventional through to the most advanced, the second edition of Turbo Coding, Turbo Equalisation and Space-Time Coding is a self-contained reference on channel coding for wireless channels. The book commences with a historical perspective on the topic, which leads to two basic component codes, convolutional and block codes. It then moves on to turbo codes which exploit iterative decoding by using algorithms, such as the Maximum-A-Posteriori (MAP), Log-MAP and Soft Output Viterbi Algorithm (SOVA), comparing their performance. It also compares Trellis Coded Modulation (TCM), Turbo Trellis Coded Modulation (TTCM), Bit-Interleaved Coded Modulation (BICM) and Iterative BICM (BICM-ID) under various channel conditions. The horizon of the content is then extended to incorporate topics which have found their way into diverse standard systems. These include space-time block and trellis codes, as well as other Multiple-Input Multiple-Output (MIMO) schemes and near-instantaneously Adaptive Quadrature Amplitude Modulation (AQAM). The book also elaborates on turbo equalisation by providing a detailed portrayal of recent advances in partial response modulation schemes using diverse channel codes. A radically new aspect for this second edition is the discussion of multi-level coding and sphere-packing schemes, Extrinsic Information Transfer (EXIT) charts, as well as an introduction to the family of Generalized Low Density Parity Check codes. This new edition includes recent advances in near-capacity turbo-transceivers as well as new sections on multi-level coding schemes and of Generalized Low Density Parity Check codes Comparatively studies diverse channel coded and turbo detected systems to give all-inclusive information for researchers, engineers and students Details EXIT-chart based irregular transceiver designs Uses rich performance comparisons as well as diverse near-capacity design examples

Download or read book Mobile and Wireless Communications written by Salma Ait Fares and published by BoD – Books on Demand. This book was released on 2010-01-01 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mobile and wireless communications applications have a clear impact on improving the humanity wellbeing. From cell phones to wireless internet to home and office devices, most of the applications are converted from wired into wireless communication. Smart and advanced wireless communication environments represent the future technology and evolutionary development step in homes, hospitals, industrial, vehicular and transportation systems. A very appealing research area in these environments has been the wireless ad hoc, sensor and mesh networks. These networks rely on ultra low powered processing nodes that sense surrounding environment temperature, pressure, humidity, motion or chemical hazards, etc. Moreover, the radio frequency (RF) transceiver nodes of such networks require the design of transmitter and receiver equipped with high performance building blocks including antennas, power and low noise amplifiers, mixers and voltage controlled oscillators. Nowadays, the researchers are facing several challenges to design such building blocks while complying with ultra low power consumption, small area and high performance constraints. CMOS technology represents an excellent candidate to facilitate the integration of the whole transceiver on a single chip. However, several challenges have to be tackled while designing and using nanoscale CMOS technologies and require innovative idea from researchers and circuits designers. While major researchers and applications have been focusing on RF wireless communication, optical wireless communication based system has started to draw some attention from researchers for a terrestrial system as well as for aerial and satellite terminals. This renewed interested in optical wireless communications is driven by several advantages such as no licensing requirements policy, no RF radiation hazards, and no need to dig up roads besides its large bandwidth and low power consumption. This second part of the book, Mobile and Wireless Communications: Key Technologies and Future Applications, covers the recent development in ad hoc and sensor networks, the implementation of state of the art of wireless transceivers building blocks and recent development on optical wireless communication systems. We hope that this book will be useful for students, researchers and practitioners in their research studies.