Results 161 to 170 of about 45,321 (190)

Analysis of practical LDPC decoders in tanner graphs with absorbing sets

2017 IEEE Information Theory Workshop (ITW), 2017
Abstract--Absorbing sets (ASs) cause the error floor phenomenon in many Low-Density Parity-Check (LDPC) codes. A recent, simplified system model for Min-Sum (MS) LDPC decoding [1] predicts that ASs exhibit a threshold behavior: if all variable nodes in an AS have channel messages above the threshold, the AS cannot trap the decoder.
Marco Ferrari, Alessandro Tomasoni, Sandro Bellini   +2 more
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Girth of the Tanner graph and error correction capability of LDPC codes

2008 46th Annual Allerton Conference on Communication, Control, and Computing, 2008
We investigate the relation between the girth and the guaranteed error correction capability of gamma-left regular LDPC codes. For column-weight-three codes, we give upper and lower bounds on the number of errors correctable by the Gallager A algorithm.
Shashi Kiran Chilappagari, Dung Viet Nguyen, Bane Vasic, Michael W. Marcellin   +3 more
openaire   +1 more source

On the Performance of Tanner Graph Based and Viterbi Decoding for Erasure Recovery

2015 IEEE 82nd Vehicular Technology Conference (VTC2015-Fall), 2015
We address the utilization of short erasure correcting codes to recover the erased data in opportunistic spectrum access (OSA) due to collisions among multiple users. The main application of using short codes over long codes is to avoid long delays in the network.
Muhammad Moazam Azeem, Abdul Baqi Khan, Uzma Azeem   +2 more
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Construction of LDPC Codes with Cycles Hold in Tanner Graph

2007 International Conference on Wireless Communications, Networking and Mobile Computing, 2007
This paper presents a algebraic method for constructing LDPC codes. It uses a parity-check matrix of a short LDPC code with given degree distribution as mother matrix, upon which a long LDPC code is constructed by circulant permutation matrices. The number of cycles of given length in the Tanner graph of constructed codes is equal to or less than that ...
Binbin Liu, Shunliang Mei, Dong Bai
openaire   +1 more source

Codes that have tanner graphs with non-overlapping cycles

2008 5th International Symposium on Turbo Codes and Related Topics, 2008
The sum-product algorithm (SPA) for the decoding of low density parity check (LDPC) codes produces exact posterior probabilities when the underlying Tanner graph is cycle-free. However, it has been shown that cycle-free Tanner graphs cannot support good codes as they have poor minimum distance properties.
S. Srimathy, Andrew Thangaraj
openaire   +1 more source

Which codes have cycle-free Tanner graphs?

IEEE Transactions on Information Theory, 1999
Summary: If a linear block code \(C\) of length \(n\) has a Tanner graph without cycles, then maximum-likelihood soft-decision decoding of \(C\) can be achieved in time \(O(n^2)\). However, we show that cycle-free Tanner graphs cannot support good codes. Specifically, let \(C\) be an \((n, k,d)\) linear code of rate \(R=k/n\) that can be represented by
Tuvi Etzion, Ari Trachtenberg, Alexander Vardy   +2 more
openaire   +1 more source

The construction of Tanner graph for iterative PN sequence acquisition

IET International Communication Conference on Wireless Mobile & Computing (CCWMC 2009), 2009
This paper proposes an improved algorithm of PEG, CPEG (Constrained Progressive Edge Growth), for constructing tanner graphs to represent the constraints of PN sequence, which makes the iterative acquisition method applicable for general PN sequences. And simulation results show that the performance of iterative acquisition using CPEG graph is improved
null Yanchao Kang, null Kai Niu
openaire   +1 more source

Binary representation of cycle Tanner-graph GF(2/sup b/) codes

2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577), 2004
We derive the average symbol and Hamming weight spectrum functions of the random ensemble of regular low-density parity-check (LDPC) codes over GF(2/sup b/) when used with the binary-input noisy channel. This work confirms theoretically that the near-Shannon-limit performance of Gallager's binary LDPC codes can be significantly enhanced by moving to ...
Xiao-Yu Hu, Evangelos Eleftheriou
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On Counting Short Cycles of LDPC Codes Using the Tanner Graph Spectrum

2018 IEEE 10th International Symposium on Turbo Codes & Iterative Information Processing (ISTC), 2018
Counting short cycles in bipartite graphs is a fundamental problem of interest in the analysis and design of low-density parity-check (LDPC) codes. The vast majority of research in this area is focused on algorithmic techniques. Most recently, Blake and Lin proposed a computational technique to count the number of cycles of length g in a bi-regular ...
Ali Dehghan 0001, Amir H. Banihashemi
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Adaptive Image Deblurring via Tanner Graph Representation and Belief Propagation

2011 Data Compression Conference, 2011
In this paper, we propose a deblurring framework based on a factor graph representation of the image and the image formation process. Each pixel is described by a variable node, while the statistical relation among pixels is formulated by two sets of check nodes, describing the local image structures and the image formation process, respectively ...
openaire   +1 more source