Affiliation:
1. Faculty of Electrical Engineering, University of Science and Technology of Oran (USTO), Algeria
2. Faculty of Technology, University of Hassiba Benbouali Chlef (UHBC), Algeria
Abstract
Since their rediscovery in the early 1990s, low-density parity-check (LDPC)
codes have become the most popular error-correcting codes owing to their
excellent performance. An LDPC code is a linear block code that has a sparse
parity-check matrix. Cycles in this matrix, particularly short cycles,
degrade the performance of such a code. Hence, several methods for counting
short cycles in LDPC codes have been proposed, such as Fan?s method to
detect 4-cycles, 6- cycles, 8-cycles, and 10-cycles. Unfortunately, this
method fails to count all 6- cycles, i.e., ignores numerous 6-cycles, in
some given parity-check matrices. In this paper, an improvement of this
algorithm is presented that detects all 6-cycles in LDPC codes, as well as
in general bipartite graphs. Simulations confirm that the improved method
offers the exact number of 6-cycles, and it succeeds in detecting those
ignored by Fan?s method.
Publisher
National Library of Serbia
Subject
Electrical and Electronic Engineering,Computer Networks and Communications,Hardware and Architecture,Mechanical Engineering,Energy Engineering and Power Technology,Control and Systems Engineering