Low Density Parity Check Codes Based on Finite Geometries
Low Density Parity Check Codes Based on Finite Geometries

Author: National Aeronautics and Space Adm Nasa

Publisher:

Published: 2018-09-15

Total Pages: 36

ISBN-13: 9781723736247

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Low density parity check (LDPC) codes with iterative decoding based on belief propagation achieve astonishing error performance close to Shannon limit. No algebraic or geometric method for constructing these codes has been reported and they are largely generated by computer search. As a result, encoding of long LDPC codes is in general very complex. This paper presents two classes of high rate LDPC codes whose constructions are based on finite Euclidean and projective geometries, respectively. These classes of codes a.re cyclic and have good constraint parameters and minimum distances. Cyclic structure adows the use of linear feedback shift registers for encoding. These finite geometry LDPC codes achieve very good error performance with either soft-decision iterative decoding based on belief propagation or Gallager's hard-decision bit flipping algorithm. These codes can be punctured or extended to obtain other good LDPC codes. A generalization of these codes is also presented.Kou, Yu and Lin, Shu and Fossorier, MarcGoddard Space Flight CenterEUCLIDEAN GEOMETRY; ALGORITHMS; DECODING; PARITY; ALGEBRA; INFORMATION THEORY; PROJECTIVE GEOMETRY; TWO DIMENSIONAL MODELS; COMPUTERIZED SIMULATION; ERRORS; BLOCK DIAGRAMS...

Construction and Decoding of Codes on Finite Fields and Finite Geometries
Construction and Decoding of Codes on Finite Fields and Finite Geometries

Author: Li Zhang

Publisher:

Published: 2010

Total Pages:

ISBN-13: 9781124319117

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In this doctoral dissertation, two constructions of binary low-density parity-check (LDPC) codes with quasi-cyclic (QC) structures are presented. A general construction of RC-constrained arrays of circulant permutation matrices is introduced, then two specific construction methods based on Latin squares and cyclic subgroups are presented. Array masking is also proposed to improve the waterfall-region performance of the QC-LDPC codes. Also, by analyzing the parity check matrices of these codes, combinatorial expressions for their ranks and dimensions are derived. Experimental results show that, with iterative decoding algorithms, the constructed codes perform very well over both the additive white Gaussian noise (AWGN) and the binary erasure channels (BEC). Also presented in this dissertation are constructions of QC-LDPC codes based on two special classes of balanced incomplete block designs (BIBDs) derived by Bose. Codes are constructed for both the AWGN channel and the binary burst erasure channel (BBEC). Experimental results show that the codes constructed perform well not only over these two types of channels but also over the BEC. Finally, a two stage iterative decoding is presented to decode a class of cyclic Euclidean geometry codes. By exploiting the inherent geometry structure of the codes and avoiding the degrading effect of short cycles, the proposed algorithm provides good decoding performance of the codes.

Classes of High-performance Quantum LDPC Codes from Finite Projective Geometries
Classes of High-performance Quantum LDPC Codes from Finite Projective Geometries

Author: Jacob M. Farinholt

Publisher:

Published: 2012

Total Pages: 0

ISBN-13:

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Due to their fast decoding algorithms, quantum generalizations of low-density parity check, or LDPC, codes have been investigated as a solution to the problem of decoherence in fragile quantum states [1, 2]. However, the additional twisted inner product requirements of quantum stabilizer codes force four-cycles and eliminate the possibility of randomly generated quantum LDPC codes. Moreover, the classes of quantum LDPC codes discovered thus far generally have unknown or small minimum distance, or a fixed rate (see [3, 4] and references therin). This paper presents several new classes of quantum LDPC codes constructed from finite projective planes. These codes have rates that increase with the block length n and minimum weights proportional to n1=2. For the sake of completeness, we include an introduction to classical error correction and LDPC codes, and provide a review of quantum communication, quantum stabilizer codes, and finite projective geometry.

Applied Algebra, Algebraic Algorithms and Error-Correcting Codes
Applied Algebra, Algebraic Algorithms and Error-Correcting Codes

Author: Marc Fossorier

Publisher: Springer

Published: 2003-08-03

Total Pages: 275

ISBN-13: 3540448284

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This book constitutes the refereed proceedings of the 15th International Symposium on Applied Algebra, Algebraic Algorithms and Error-Correcting Codes, AAECC-15, held in Toulouse, France, in May 2003.The 25 revised full papers presented together with 2 invited papers were carefully reviewed and selected from 40 submissions. Among the subjects addressed are block codes; algebra and codes: rings, fields, and AG codes; cryptography; sequences; decoding algorithms; and algebra: constructions in algebra, Galois groups, differential algebra, and polynomials.

Codes, Graphs, and Systems
Codes, Graphs, and Systems

Author: Richard E. Blahut

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 458

ISBN-13: 1461508959

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Foreword by James L. Massey. Codes, Graphs, and Systems is an excellent reference for both academic researchers and professional engineers working in the fields of communications and signal processing. A collection of contributions from world-renowned experts in coding theory, information theory, and signal processing, the book provides a broad perspective on contemporary research in these areas. Survey articles are also included. Specific topics covered include convolutional codes and turbo codes; detection and equalization; modems; physics and information theory; lattices and geometry; and behaviors and codes on graphs. Codes, Graphs, and Systems is a tribute to the leadership and profound influence of G. David Forney, Jr. The 35 contributors to the volume have assembled their work in his honor.

Error-Correction Coding and Decoding
Error-Correction Coding and Decoding

Author: Martin Tomlinson

Publisher: Springer

Published: 2017-02-21

Total Pages: 527

ISBN-13: 3319511033

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This book discusses both the theory and practical applications of self-correcting data, commonly known as error-correcting codes. The applications included demonstrate the importance of these codes in a wide range of everyday technologies, from smartphones to secure communications and transactions. Written in a readily understandable style, the book presents the authors’ twenty-five years of research organized into five parts: Part I is concerned with the theoretical performance attainable by using error correcting codes to achieve communications efficiency in digital communications systems. Part II explores the construction of error-correcting codes and explains the different families of codes and how they are designed. Techniques are described for producing the very best codes. Part III addresses the analysis of low-density parity-check (LDPC) codes, primarily to calculate their stopping sets and low-weight codeword spectrum which determines the performance of th ese codes. Part IV deals with decoders designed to realize optimum performance. Part V describes applications which include combined error correction and detection, public key cryptography using Goppa codes, correcting errors in passwords and watermarking. This book is a valuable resource for anyone interested in error-correcting codes and their applications, ranging from non-experts to professionals at the forefront of research in their field. This book is open access under a CC BY 4.0 license.