3 research outputs found
On the guaranteed error correction capability of LDPC codes
We investigate the relation between the girth and the guaranteed error
correction capability of -left regular LDPC codes when decoded using
the bit flipping (serial and parallel) algorithms. A lower bound on the number
of variable nodes which expand by a factor of at least is found
based on the Moore bound. An upper bound on the guaranteed correction
capability is established by studying the sizes of smallest possible trapping
sets.Comment: 5 pages, submitted to IEEE International Symposium on Information
Theory (ISIT), 200
On Trapping Sets and Guaranteed Error Correction Capability of LDPC Codes and GLDPC Codes
The relation between the girth and the guaranteed error correction capability
of -left regular LDPC codes when decoded using the bit flipping (serial
and parallel) algorithms is investigated. A lower bound on the size of variable
node sets which expand by a factor of at least is found based on
the Moore bound. An upper bound on the guaranteed error correction capability
is established by studying the sizes of smallest possible trapping sets. The
results are extended to generalized LDPC codes. It is shown that generalized
LDPC codes can correct a linear fraction of errors under the parallel bit
flipping algorithm when the underlying Tanner graph is a good expander. It is
also shown that the bound cannot be improved when is even by studying
a class of trapping sets. A lower bound on the size of variable node sets which
have the required expansion is established.Comment: 17 pages. Submitted to IEEE Transactions on Information Theory. Parts
of this work have been accepted for presentation at the International
Symposium on Information Theory (ISIT'08) and the International Telemetering
Conference (ITC'08