The Benefit of Thresholding in LP Decoding of LDPC Codes
Abstract
Consider data transmission over a binary-input additive white Gaussian noise channel using a binary low-density parity-check code. We ask the following question: Given a decoder that takes log-likelihood ratios as input, does it help to modify the log-likelihood ratios before decoding? If we use an optimal decoder then it is clear that modifying the log-likelihoods cannot possibly help the decoder's performance, and so the answer is "no." However, for a suboptimal decoder like the linear programming decoder, the answer might be "yes": In this paper we prove that for certain interesting classes of low-density parity-check codes and large enough SNRs, it is advantageous to truncate the log-likelihood ratios before passing them to the linear programming decoder.
Cite
@article{arxiv.cs/0508014,
title = {The Benefit of Thresholding in LP Decoding of LDPC Codes},
author = {Jon Feldman and Ralf Koetter and Pascal O. Vontobel},
journal= {arXiv preprint arXiv:cs/0508014},
year = {2016}
}
Comments
To appear in Proc. 2005 IEEE International Symposium on Information Theory, Adelaide, Australia, September 4-9, 2005