5 research outputs found
Extended Non-Binary Low-Density Parity-Check Codes over Erasure Channels
Based on the extended binary image of non-binary LDPC codes, we propose a
method for generating extra redundant bits, such as to decreases the coding
rate of a mother code. The proposed method allows for using the same decoder,
regardless of how many extra redundant bits have been produced, which
considerably increases the flexibility of the system without significantly
increasing its complexity. Extended codes are also optimized for the binary
erasure channel, by using density evolution methods. Nevertheless, the results
presented in this paper can easily be extrapolated to more general channel
models.Comment: ISIT 2011, submitte
Enhancing Binary Images of Non-Binary LDPC Codes
We investigate the reasons behind the superior performance of belief
propagation decoding of non-binary LDPC codes over their binary images when the
transmission occurs over the binary erasure channel. We show that although
decoding over the binary image has lower complexity, it has worse performance
owing to its larger number of stopping sets relative to the original non-binary
code. We propose a method to find redundant parity-checks of the binary image
that eliminate these additional stopping sets, so that we achieve performance
comparable to that of the original non-binary LDPC code with lower decoding
complexity.Comment: 6 pages, 2 figures, to be presented at IEEE GLOBECOM 201