Constrained Coding and Soft Iterative Decoding

Constrained Coding and Soft Iterative Decoding PDF Author: John L. Fan
Publisher: Springer Science & Business Media
ISBN: 1461515254
Category : Technology & Engineering
Languages : en
Pages : 268

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Book Description
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.

Constrained Coding and Soft Iterative Decoding

Constrained Coding and Soft Iterative Decoding PDF Author: John L. Fan
Publisher: Springer Science & Business Media
ISBN: 1461515254
Category : Technology & Engineering
Languages : en
Pages : 268

Get Book Here

Book Description
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.

Constrained Coding and Soft Iterative Decoding for Storage

Constrained Coding and Soft Iterative Decoding for Storage PDF Author: John L. Fan
Publisher:
ISBN:
Category :
Languages : en
Pages : 302

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Book Description


Advanced Error Control Techniques for Data Storage Systems

Advanced Error Control Techniques for Data Storage Systems PDF Author: Erozan M. Kurtas
Publisher: CRC Press
ISBN: 1420036491
Category : Computers
Languages : en
Pages : 288

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Book Description
With the massive amount of data produced and stored each year, reliable storage and retrieval of information is more crucial than ever. Robust coding and decoding techniques are critical for correcting errors and maintaining data integrity. Comprising chapters thoughtfully selected from the highly popular Coding and Signal Processing for Magnetic Recording Systems, Advanced Error Control Techniques for Data Storage Systems is a finely focused reference to the state-of-the-art error control and modulation techniques used in storage devices. The book begins with an introduction to error control codes, explaining the theory and basic concepts underlying the codes. Building on these concepts, the discussion turns to modulation codes, paying special attention to run-length limited sequences, followed by maximum transition run (MTR) and spectrum shaping codes. It examines the relationship between constrained codes and error control and correction systems from both code-design and architectural perspectives as well as techniques based on convolution codes. With a focus on increasing data density, the book also explores multi-track systems, soft decision decoding, and iteratively decodable codes such as Low-Density Parity-Check (LDPC) Codes, Turbo codes, and Turbo Product Codes. Advanced Error Control Techniques for Data Storage Systems offers a comprehensive collection of theory and techniques that is ideal for specialists working in the field of data storage systems.

Encyclopedia of Optical and Photonic Engineering (Print) - Five Volume Set

Encyclopedia of Optical and Photonic Engineering (Print) - Five Volume Set PDF Author: Craig Hoffman
Publisher: CRC Press
ISBN: 1351247174
Category : Science
Languages : en
Pages : 3726

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Book Description
The first edition of the Encyclopedia of Optical and Photonic Engineering provided a valuable reference concerning devices or systems that generate, transmit, measure, or detect light, and to a lesser degree, the basic interaction of light and matter. This Second Edition not only reflects the changes in optical and photonic engineering that have occurred since the first edition was published, but also: Boasts a wealth of new material, expanding the encyclopedia’s length by 25 percent Contains extensive updates, with significant revisions made throughout the text Features contributions from engineers and scientists leading the fields of optics and photonics today With the addition of a second editor, the Encyclopedia of Optical and Photonic Engineering, Second Edition offers a balanced and up-to-date look at the fundamentals of a diverse portfolio of technologies and discoveries in areas ranging from x-ray optics to photon entanglement and beyond. This edition’s release corresponds nicely with the United Nations General Assembly’s declaration of 2015 as the International Year of Light, working in tandem to raise awareness about light’s important role in the modern world. Also Available Online This Taylor & Francis encyclopedia is also available through online subscription, offering a variety of extra benefits for researchers, students, and librarians, including: Citation tracking and alerts Active reference linking Saved searches and marked lists HTML and PDF format options Contact Taylor and Francis for more information or to inquire about subscription options and print/online combination packages. US: (Tel) 1.888.318.2367; (E-mail) [email protected] International: (Tel) +44 (0) 20 7017 6062; (E-mail) [email protected]

Coding for Optical Channels

Coding for Optical Channels PDF Author: Ivan Djordjevic
Publisher: Springer Science & Business Media
ISBN: 1441955690
Category : Technology & Engineering
Languages : en
Pages : 454

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Book Description
In order to adapt to the ever-increasing demands of telecommunication needs, today’s network operators are implementing 100 Gb/s per dense wavelength division multiplexing (DWDM) channel transmission. At those data rates, the performance of fiberoptic communication systems is degraded significantly due to intra- and inter-channel fiber nonlinearities, polarization-mode dispersion (PMD), and chromatic dispersion. In order to deal with those channel impairments, novel advanced techniques in modulation and detection, coding and signal processing are needed. This unique book represents a coherent and comprehensive introduction to the fundamentals of optical communications, signal processing and coding for optical channels. It is the first to integrate the fundamentals of coding theory with the fundamentals of optical communication.

Symbolic Dynamics and its Applications

Symbolic Dynamics and its Applications PDF Author: Susan G. Williams
Publisher: American Mathematical Soc.
ISBN: 0821831577
Category : Mathematics
Languages : en
Pages : 168

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Book Description
Symbolic dynamics originated as a tool for analyzing dynamical systems and flows by discretizing space as well as time. The development of information theory gave impetus to the study of symbol sequences as objects in their own right. Today, symbolic dynamics has expanded to encompass multi-dimensional arrays of symbols and has found diverse applications both within and beyond mathematics. This volume is based on the AMS Short Course on Symbolic Dynamics and its Applications. It contains introductory articles on the fundamental ideas of the field and on some of its applications. Topics include the use of symbolic dynamics techniques in coding theory and in complex dynamics, the relation between the theory of multi-dimensional systems and the dynamics of tilings, and strong shift equivalence theory. Contributors to the volume are experts in the field and are clear expositors. The book is suitable for graduate students and research mathematicians interested in symbolic dynamics and its applications.

Coding and Signal Processing for Magnetic Recording Systems

Coding and Signal Processing for Magnetic Recording Systems PDF Author: Bane Vasic
Publisher: CRC Press
ISBN: 0203490312
Category : Computers
Languages : en
Pages : 742

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Book Description
Implementing new architectures and designs for the magnetic recording read channel have been pushed to the limits of modern integrated circuit manufacturing technology. This book reviews advanced coding and signal processing techniques and architectures for magnetic recording systems. Beginning with the basic principles, it examines read/write operations, data organization, head positioning, sensing, timing recovery, data detection, and error correction. It also provides an in-depth treatment of all recording channel subsystems inside a read channel and hard disk drive controller. The final section reviews new trends in coding, particularly emerging codes for recording channels.

Fundamentals of Codes, Graphs, and Iterative Decoding

Fundamentals of Codes, Graphs, and Iterative Decoding PDF Author: Stephen B. Wicker
Publisher: Springer Science & Business Media
ISBN: 0306477947
Category : Technology & Engineering
Languages : en
Pages : 241

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Book Description
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.

Turbo-like Codes

Turbo-like Codes PDF Author: Aliazam Abbasfar
Publisher: Springer Science & Business Media
ISBN: 1402063911
Category : Technology & Engineering
Languages : en
Pages : 94

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Book Description
This book introduces turbo error correcting concept in a simple language, including a general theory and the algorithms for decoding turbo-like code. It presents a unified framework for the design and analysis of turbo codes and LDPC codes and their decoding algorithms. A major focus is on high speed turbo decoding, which targets applications with data rates of several hundred million bits per second (Mbps).

Iterative Decoding for Trellis Based Codes in Wireless Communications

Iterative Decoding for Trellis Based Codes in Wireless Communications PDF Author: Huijun Chen
Publisher:
ISBN:
Category :
Languages : en
Pages : 240

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Book Description
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.