TITLE:
Tree Matrix Algorithm of LDPC Codes
AUTHORS:
Huanming Zhang
KEYWORDS:
LDPC, Belief Propagation (BP), Graph, Iterative Decoding, Loop, Cycle
JOURNAL NAME:
Journal of Signal and Information Processing,
Vol.5 No.4,
November
19,
2014
ABSTRACT: LDPC codes are finding
increasing use in applications requiring reliable and highly efficient
information transfer over bandwidth. An LDPC code is defined by a sparse
parity-check matrix and can be described by a bipartite graph called Tanner
graph. Loops in Tanner graph prevent the sum-product algorithm from converging.
Further, loops, especially short loops, degrade the performance of LDPC
decoder, because they affect the independence of the extrinsic information
exchanged in the iterative decoding. This paper, by graph theory, deduces
cut-node tree graph of LDPC code, and depicts it with matrix. On the basis of
tree matrix algorithm, whole depictions of loops can be figured out, providing
of foundation for further research of relations between loops and LDPC codes’
performance.