Results 201 to 210 of about 37,003 (218)

Low Density Parity Check Codes

2016
Besides the turbo codes, there is one more class of linear block codes that makes possible to approach to the Shannon bound. These are Low Density Parity Check (LDPC) codes. They were proposed by Gallager [83]. In principle they have a sparse parity - check matrix.
Predrag Ivaniš, Dušan Drajić
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Low Density Parity Check Codes

2014
The Tanner graph is described. A girth in the Tanner graph is equivalent to a short cycle of 1- symbols in the parity check matrix. The condition called row-column constraint is introduced, in order to allow practical decoding procedures. They are based on the sum-product algorithm, which is briefly outlined.
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Low-Density Parity-Check Codes

2000
Gallager first proposed low-density parity-check (LDPC) codes and their iterative detection algorithm in 1962 [Gallager, 1962]. They have been almost forgotten for thirty years. Recently, with the extensive research on “turbo-like” codes and on iterative detection, LDPC codes re-emerge as another category of random codes approaching the Shannon ...
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Low-Density Parity-Check Codes

1963
This is a complete presentation of all important theoretical and experimental work done on low-density codes. Low-density coding is one of the three techniques thus far developed for efficient communication over noisy channels with an arbitrarily low probability of error. A principal result of information theory is that if properly coded information is
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Constructing low-density parity-check codes

IEEE/AFCEA EUROCOMM 2000. Information Systems for Enhanced Public Safety and Security (Cat. No.00EX405), 2002
A low-density parity-check code (LDPCC) has been constructed for a block size of 10/sup 7/ that provides performance within 0.01 dB of Shannon's limit using iterative belief propagation (IBP) decoding. The LDPCC can be constructed for nearly any code rate and block size and encoding and IBP decoding is practical for many applications. We describe LDPCC
J.W. Bond, S. Hui, H. Schmidt
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Low-density parity-check accumulate codes

2010 International Symposium On Information Theory & Its Applications, 2010
This paper presents a class of high-rate codes called low-density parity-check accumulate (LDPCA) codes. The code design is the serial concatenation of an LDPC outer code and an accumulator with an interleaver. The iterative decoding for the LDPCA code design has complexity linear to the code length.
Chung-Li Wang, Shu Lin
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Quasicyclic low density parity check codes

IEEE International Symposium on Information Theory, 2003. Proceedings., 2003
In this work, the construction of low density parity check codes (LDPCs) from circulant permutation matrices is investigated. It is shown that such codes can not have a Tanner graph representation with girth larger than 12, and a relatively loose necessary and sufficient condition for the code to have a girth of 6, 8, 10 or 12 is derived. These results
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Low-Density Parity-Check Codes

2013
Low-density parity-check (LDPC) codes were introduced in 1960 by R. Gallager [1] in his Phd thesis. He already introduced the iterative method for decoding LDPC codes. However, also due to their computational and implementation complexity the iterative decoding was largely ignored.
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Low Density Parity Check Codes

2015
Low density parity check (LDPC) codes are forward error-correction codes, invented by Robert Gallager in his MIT Ph.D. dissertation, 1960. The LDPC codes are ignored for long time due to their high computational complexity and domination of highly structured algebraic block and convolutional codes for forward error correction.
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Low-density parity check codes over GF(q)

IEEE Communications Letters, 1998
Gallager's (1962) low-density binary parity check codes have been shown to have near-Shannon limit performance when decoded using a probabilistic decoding algorithm. We report the empirical results of error-correction using the analogous codes over GF(q) for q>2, with binary symmetric channels and binary Gaussian channels.
M.C. Davey, D.J.C. MacKay
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