Download or read book Iterative Trellis Decoding for Block Codes written by Frédéric Fontaine (Michel) and published by . This book was released on 1999 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Trellises and Trellis Based Decoding Algorithms for Linear Block Codes written by Shu Lin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the demand for data reliability increases, coding for error control becomes increasingly important in data transmission systems and has become an integral part of almost all data communication system designs. In recent years, various trellis-based soft-decoding algorithms for linear block codes have been devised. New ideas developed in the study of trellis structure of block codes can be used for improving decoding and analyzing the trellis complexity of convolutional codes. These recent developments provide practicing communication engineers with more choices when designing error control systems. Trellises and Trellis-based Decoding Algorithms for Linear Block Codes combines trellises and trellis-based decoding algorithms for linear codes together in a simple and unified form. The approach is to explain the material in an easily understood manner with minimal mathematical rigor. Trellises and Trellis-based Decoding Algorithms for Linear Block Codes is intended for practicing communication engineers who want to have a fast grasp and understanding of the subject. Only material considered essential and useful for practical applications is included. This book can also be used as a text for advanced courses on the subject.

Download or read book Trellises and Trellis Based Decoding Algorithms for Linear Block Codes Part 3 An Iterative Decoding Algorithm for Linear Block Codes Based on a Low written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-18 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: For long linear block codes, maximum likelihood decoding based on full code trellises would be very hard to implement if not impossible. In this case, we may wish to trade error performance for the reduction in decoding complexity. Sub-optimum soft-decision decoding of a linear block code based on a low-weight sub-trellis can be devised to provide an effective trade-off between error performance and decoding complexity. This chapter presents such a suboptimal decoding algorithm for linear block codes. This decoding algorithm is iterative in nature and based on an optimality test. It has the following important features: (1) a simple method to generate a sequence of candidate code-words, one at a time, for test; (2) a sufficient condition for testing a candidate code-word for optimality; and (3) a low-weight sub-trellis search for finding the most likely (ML) code-word. Lin, Shu and Fossorier, Marc Goddard Space Flight Center NAG5-931; NAG5-2938

Download or read book Trellises and Trellis Based Decoding Algorithms for Linear Block Codes Part 3 An Iterative Decoding Algorithm for Linear Block Codes Based on a Low Weight Trellis Search written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-15 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: For long linear block codes, maximum likelihood decoding based on full code trellises would be very hard to implement if not impossible. In this case, we may wish to trade error performance for the reduction in decoding complexity. Sub-optimum soft-decision decoding of a linear block code based on a low-weight sub-trellis can be devised to provide an effective trade-off between error performance and decoding complexity. This chapter presents such a suboptimal decoding algorithm for linear block codes. This decoding algorithm is iterative in nature and based on an optimality test. It has the following important features: (1) a simple method to generate a sequence of candidate code-words, one at a time, for test; (2) a sufficient condition for testing a candidate code-word for optimality; and (3) a low-weight sub-trellis search for finding the most likely (ML) code-word. Lin, Shu and Fossorier, Marc Goddard Space Flight Center NAG5-931; NAG5-2938...

Download or read book Trellis and Turbo Coding written by Christian B. Schlegel and published by John Wiley & Sons. This book was released on 2015-08-19 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new edition has been extensively revised to reflect the progress in error control coding over the past few years. Over 60% of the material has been completely reworked, and 30% of the material is original. Convolutional, turbo, and low density parity-check (LDPC) coding and polar codes in a unified framework Advanced research-related developments such as spatial coupling A focus on algorithmic and implementation aspects of error control coding

Download or read book Constrained Coding and Soft Iterative Decoding written by John L. Fan and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Constrained Coding and Soft Iterative Decoding is the first work to combine the issues of constrained coding and soft iterative decoding (e.g., turbo and LDPC codes) from a unified point of view. Since constrained coding is widely used in magnetic and optical storage, it is necessary to use some special techniques (modified concatenation scheme or bit insertion) in order to apply soft iterative decoding. Recent breakthroughs in the design and decoding of error-control codes (ECCs) show significant potential for improving the performance of many communications systems. ECCs such as turbo codes and low-density parity check (LDPC) codes can be represented by graphs and decoded by passing probabilistic (a.k.a. `soft') messages along the edges of the graph. This message-passing algorithm yields powerful decoders whose performance can approach the theoretical limits on capacity. This exposition uses `normal graphs,' introduced by Forney, which extend in a natural manner to block diagram representations of the system and provide a simple unified framework for the decoding of ECCs, constrained codes, and channels with memory. Soft iterative decoding is illustrated by the application of turbo codes and LDPC codes to magnetic recording channels. For magnetic and optical storage, an issue arises in the use of constrained coding, which places restrictions on the sequences that can be transmitted through the channel; the use of constrained coding in combination with soft ECC decoders is addressed by the modified concatenation scheme also known as `reverse concatenation.' Moreover, a soft constraint decoder yields additional coding gain from the redundancy in the constraint, which may be of practical interest in the case of optical storage. In addition, this monograph presents several other research results (including the design of sliding-block lossless compression codes, and the decoding of array codes as LDPC codes). Constrained Coding and Soft Iterative Decoding will prove useful to students, researchers and professional engineers who are interested in understanding this new soft iterative decoding paradigm and applying it in communications and storage systems.

Download or read book Trellis based Iterative Decoding of Block Codes for Satellite ATM written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Trellises and Trellis Based Decoding Algorithms for Linear Block Codes Part 3 The Map and Related Decoding Algirithms written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-24 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a coded communication system with equiprobable signaling, MLD minimizes the word error probability and delivers the most likely codeword associated with the corresponding received sequence. This decoding has two drawbacks. First, minimization of the word error probability is not equivalent to minimization of the bit error probability. Therefore, MLD becomes suboptimum with respect to the bit error probability. Second, MLD delivers a hard-decision estimate of the received sequence, so that information is lost between the input and output of the ML decoder. This information is important in coded schemes where the decoded sequence is further processed, such as concatenated coding schemes, multi-stage and iterative decoding schemes. In this chapter, we first present a decoding algorithm which both minimizes bit error probability, and provides the corresponding soft information at the output of the decoder. This algorithm is referred to as the MAP (maximum aposteriori probability) decoding algorithm. Lin, Shu and Fossorier, Marc Goddard Space Flight Center NAG5-931; NAG5-2938

Download or read book Trellis Decoding of 3 D Block Turbo Codes written by Bo Yin and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Forward Error Correction (FEC) technique provides a method to detect and correct errors in transmitted data. It is also a valuable technique to reduce the power requirement, thus have an important role in these systems. This reduction in power requirement is achieved at the expense of an increase in bandwidth requirement. The objective is usually to find error control techniques that give good tradeoff between power and bandwidth requirements. In this thesis, we present results for FEC technique using Turbo Block Codes and Turbo Product Codes. It is shown that these codes, not only in theory but also in hardware implementation, are capable of providing significant performance gains over other error-correction schemes. This thesis investigates Trellis based iterative decoding techniques applied to concatenated coding schemes, Turbo Block Codes. We use RM(n, k) to construct 2-D and multi-dimensional Turbo Block Codes. Our objective is to get high code rates and long block sizes for more bandwidth efficiency and improving the performance of the optimised maximum a posterior decoding algorithm.

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 Tail Biting Trellis Representation of Codes written by National Aeronautics and Space Adm Nasa and published by . This book was released on 2018-09-21 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents two new iterative algorithms for decoding linear codes based on their tail biting trellises, one is unidirectional and the other is bidirectional. Both algorithms are computationally efficient and achieves virtually optimum error performance with a small number of decoding iterations. They outperform all the previous suboptimal decoding algorithms. The bidirectional algorithm also reduces decoding delay. Also presented in the paper is a method for constructing tail biting trellises for linear block codes.Shao. Rose Y. and Lin, Shu and Fossorier, MarcGoddard Space Flight CenterALGORITHMS; APPLICATIONS PROGRAMS (COMPUTERS); TRELLIS CODING; MATHEMATICAL MODELS; VITERBI DECODERS; COMPUTERIZED SIMULATION; FLOW CHARTS; ITERATION; BLOCK DIAGRAMS; MATRICES (MATHEMATICS); CONVOLUTION INTEGRALS...

Download or read book Iterative Decoding for Trellis Based Codes in Wireless Communications written by Huijun Chen and published by . This book was released on 2008 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In this dissertation, we focus on three issues of the trellis based iterative decoding: First, the complexity issue of Turbo code is considered. We propose a constrained iterative decoder to reduce the decoding complexity. An additional interleaver is introduced at the encoder. At the decoder, we first use Cyclic Redundance Code (CRC) to detect which bits are already correctly decoded during early iterations. With knowledge of the positions of these correct bits, the constrained decoding algorithm is designed to reduce the number of the state transitions in the component code trellis and help the decoding of other bits in later iterations. In this way, the constrained iterative decoder achieves significant complexity reduction and still satisfying performance. Second, the iterative decoding algorithm is redesigned for Turbo code implemented Distributed Source Coding (DSC). When used in DSC, the Turbo decoder encounters a combined Binary Symmetric Channel (BSC) and Addictive White Gaussian Noise (AWGN) distortion. The existing iterative decoding algorithm based on AWGN distortion assumption causes performance degradation. By redefining the channel reliability values, the modified iterative decoding algorithm matches the BSC-AWGN scenario well and improves the performance. Third, we propose a reliable source transmission coding and decoding scheme. A serially concatenated source and space time modulated coding structure is used. Variable Length Code (VLC) with error resilient capability is adopted at the application layer. Space Time Trellis Code (STTC) is used to provide high bandwidth efficiency at the physical layer. An iterative joint source space time decoder is designed including the symbol level space time Maximum A Posteriori (MAP) decoder, the bit level VLC MAP decoder and the Viterbi VLC decoder. Critical issues such as STTC MAP algorithm with nonseparable systematic information, VLC MAP algorithm in absence of channel output, VLC Viterbi algorithm based on the bit level trellis and extrinsic information conversion and exchange between bit domain and symbol domain are addressed. The decoding performance of different frame sizes and different component VLCs and STTCs, the rate allocation between the source code and the space time code and the performance in presence of channel estimation errors are discussed in this dissertation.

Download or read book Trellises and Trellis Based Decoding Algorithms for Linear Block Codes written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-20 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Decoding algorithms based on the trellis representation of a code (block or convolutional) drastically reduce decoding complexity. The best known and most commonly used trellis-based decoding algorithm is the Viterbi algorithm. It is a maximum likelihood decoding algorithm. Convolutional codes with the Viterbi decoding have been widely used for error control in digital communications over the last two decades. This chapter is concerned with the application of the Viterbi decoding algorithm to linear block codes. First, the Viterbi algorithm is presented. Then, optimum sectionalization of a trellis to minimize the computational complexity of a Viterbi decoder is discussed and an algorithm is presented. Some design issues for IC (integrated circuit) implementation of a Viterbi decoder are considered and discussed. Finally, a new decoding algorithm based on the principle of compare-select-add is presented. This new algorithm can be applied to both block and convolutional codes and is more efficient than the conventional Viterbi algorithm based on the add-compare-select principle. This algorithm is particularly efficient for rate 1/n antipodal convolutional codes and their high-rate punctured codes. It reduces computational complexity by one-third compared with the Viterbi algorithm. Lin, Shu Goddard Space Flight Center NAG5-931; NAG5-2938...

Download or read book Fundamentals of Codes Graphs and Iterative Decoding written by Stephen B. Wicker and published by Springer Science & Business Media. This book was released on 2006-04-18 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Codes, Graphs, and Iterative Decoding is an explanation of how to introduce local connectivity, and how to exploit simple structural descriptions. Chapter 1 provides an overview of Shannon theory and the basic tools of complexity theory, communication theory, and bounds on code construction. Chapters 2 - 4 provide an overview of "classical" error control coding, with an introduction to abstract algebra, and block and convolutional codes. Chapters 5 - 9 then proceed to systematically develop the key research results of the 1990s and early 2000s with an introduction to graph theory, followed by chapters on algorithms on graphs, turbo error control, low density parity check codes, and low density generator codes.

Download or read book Trellises and Trellis Based Decoding Algorithms for Linear Block Codes Part 3 a Recursive Maximum Likelihood Decoding written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-15 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Viterbi algorithm is indeed a very simple and efficient method of implementing the maximum likelihood decoding. However, if we take advantage of the structural properties in a trellis section, other efficient trellis-based decoding algorithms can be devised. Recently, an efficient trellis-based recursive maximum likelihood decoding (RMLD) algorithm for linear block codes has been proposed. This algorithm is more efficient than the conventional Viterbi algorithm in both computation and hardware requirements. Most importantly, the implementation of this algorithm does not require the construction of the entire code trellis, only some special one-section trellises of relatively small state and branch complexities are needed for constructing path (or branch) metric tables recursively. At the end, there is only one table which contains only the most likely code-word and its metric for a given received sequence r = (r(sub 1), r(sub 2), ..., r(sub n)). This algorithm basically uses the divide and conquer strategy. Furthermore, it allows parallel/pipeline processing of received sequences to speed up decoding. Lin, Shu and Fossorier, Marc Goddard Space Flight Center NAG5-931; NAG5-2938.

Download or read book Turbo Coding Turbo Equalisation and Space Time Coding for Transmission over Fading Channels written by Lajos L. Hanzo and published by Wiley-IEEE Press. This book was released on 2002-09-09 with total page 766 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbo coding has opened an exciting new chapter in the design of iterative detection assisted communication systems. Similar dramatic advances have been achieved with the advent of space time coding, when communicating over dispersive fading wireless channels. By assuming no prior knowledge in the field of channel coding, the authors provide a self-contained reference on these stimulating hot topics, concluding at an advanced level. This essential volume is divided into five key parts: 1. Convolutional and Block Coding Introduces the family of convolutional codes, hard and soft-decision Viterbi algorithms and the most prominent classes of block codes, namely Reed-Solomon (RS) and Bose-Chaudhuri-Hocquenghem (BCH) codes, as well as their algebraic and trellis-decoding. 2. Turbo Convolutional and Turbo Block Coding Introduces turbo convolutional codes and details the Maximum A-Posteriori (MAP), Log-MAP and Max-Log-MAP as well as the Soft Output Viterbi Algorithm (SOVA). Investigates the effects of the various turbo codec parameters. Studies the super-trellis structure of turbo codes and characterises turbo BCH codes. Portrays Redundant Residue Number System (RRNS) based codes and their turbo decoding. 3. Coded Modulation: TCM, TTCM, BICM, BICM-ID Studies Trellis Coded Modulation (TCM), Turbo Trellis Coded Modulation (TTCM), Bit-Interleaved Coded Modulation (BICM), Iterative BICM (BICM-ID) and compares them under various channel conditions. 4. Space-Time Block and Space-Time Trellis Coding Introduces space-time codes and studies their performance using numerous channel codecs providing guidelines for system designers. Studies Multiple-Input Multiple-Output (MIMO) based schemes and the concept of near-instantaneously Adaptive Quadrature Amplitude Modulation (AQAM) combined with near-instantaneously adaptive turbo channel coding. 5. Turbo Equalisation Covers the principle in detail, provides theoretical performance bounds for turbo equalisers and includes a study of various turbo equaliser arrangements. Also addresses the problem of reduced implementation complexity and covers turbo equalised space-time trellis codes. If you are looking for a comprehensive treatment covering both classic channel coding techniques and recent advances in this field, then this is the book for you. Researchers, practising engineers and advanced students will all find it both informative and stimulating.

Download or read book Fundamentals of Convolutional Coding written by Rolf Johannesson and published by John Wiley & Sons. This book was released on 2015-07-07 with total page 686 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Convolutional Coding, Second Edition, regarded as a bible of convolutional coding brings you a clear and comprehensive discussion of the basic principles of this field Two new chapters on low-density parity-check (LDPC) convolutional codes and iterative coding Viterbi, BCJR, BEAST, list, and sequential decoding of convolutional codes Distance properties of convolutional codes Includes a downloadable solutions manual