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Coupled LDPC Codes: Complexity Aspects of Threshold Saturation

Lentmaier, Michael LU and Fettweis, Gerhard (2011) IEEE Information Theory Workshop (ITW), 2011 In [Host publication title missing] p.668-672
Abstract
We analyze the convergence behavior of iteratively decoded coupled LDPC codes from a complexity point of view. It can be observed that the thresholds of coupled regular LDPC codes approach capacity as the node degrees and the number L of coupled blocks tend to infinity. The absence of degree two variable nodes in these capacity achieving ensembles implies for any fixed L a doubly exponential decrease of the error probability with the number of decoding iterations I, which guarantees a vanishing block error probability as the overall length n of the coupled codes tends to infinity at a complexity of O(n log n). On the other hand, an initial number of iterations Ibr is required until this doubly exponential decrease can be guaranteed, which... (More)
We analyze the convergence behavior of iteratively decoded coupled LDPC codes from a complexity point of view. It can be observed that the thresholds of coupled regular LDPC codes approach capacity as the node degrees and the number L of coupled blocks tend to infinity. The absence of degree two variable nodes in these capacity achieving ensembles implies for any fixed L a doubly exponential decrease of the error probability with the number of decoding iterations I, which guarantees a vanishing block error probability as the overall length n of the coupled codes tends to infinity at a complexity of O(n log n). On the other hand, an initial number of iterations Ibr is required until this doubly exponential decrease can be guaranteed, which for the standard flooding schedule increases linearly with L. This dependence of the decoding complexity on L can be avoided by means of efficient message passing schedules that account for the special structure of the coupled ensembles. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
spatial coupling, LDPC codes, LDPC convolutional codes
in
[Host publication title missing]
pages
668 - 672
publisher
IEEE--Institute of Electrical and Electronics Engineers Inc.
conference name
IEEE Information Theory Workshop (ITW), 2011
external identifiers
  • scopus:83655191074
ISBN
978-1-4577-0438-3
DOI
10.1109/ITW.2011.6089581
language
English
LU publication?
no
id
09cb1e65-5e9e-42f6-897e-e83889cd72d9 (old id 3731141)
date added to LUP
2013-04-26 10:18:05
date last changed
2017-03-05 04:24:55
@inproceedings{09cb1e65-5e9e-42f6-897e-e83889cd72d9,
  abstract     = {We analyze the convergence behavior of iteratively decoded coupled LDPC codes from a complexity point of view. It can be observed that the thresholds of coupled regular LDPC codes approach capacity as the node degrees and the number L of coupled blocks tend to infinity. The absence of degree two variable nodes in these capacity achieving ensembles implies for any fixed L a doubly exponential decrease of the error probability with the number of decoding iterations I, which guarantees a vanishing block error probability as the overall length n of the coupled codes tends to infinity at a complexity of O(n log n). On the other hand, an initial number of iterations Ibr is required until this doubly exponential decrease can be guaranteed, which for the standard flooding schedule increases linearly with L. This dependence of the decoding complexity on L can be avoided by means of efficient message passing schedules that account for the special structure of the coupled ensembles.},
  author       = {Lentmaier, Michael and Fettweis, Gerhard},
  booktitle    = {[Host publication title missing]},
  isbn         = {978-1-4577-0438-3},
  keyword      = {spatial coupling,LDPC codes,LDPC convolutional codes},
  language     = {eng},
  pages        = {668--672},
  publisher    = {IEEE--Institute of Electrical and Electronics Engineers Inc.},
  title        = {Coupled LDPC Codes: Complexity Aspects of Threshold Saturation},
  url          = {http://dx.doi.org/10.1109/ITW.2011.6089581},
  year         = {2011},
}