524 research outputs found
A Fast Convergence Density Evolution Algorithm for Optimal Rate LDPC Codes in BEC
We derive a new fast convergent Density Evolution algorithm for finding
optimal rate Low-Density Parity-Check (LDPC) codes used over the binary erasure
channel (BEC). The fast convergence property comes from the modified Density
Evolution (DE), a numerical method for analyzing the behavior of iterative
decoding convergence of a LDPC code. We have used the method of [16] for
designing of a LDPC code with optimal rate. This has been done for a given
parity check node degree distribution, erasure probability and specified DE
constraint. The fast behavior of DE and found optimal rate with this method
compare with the previous DE constraint.Comment: This Paper is a draft of final paper which represented in 7th
International Symposium on Telecommunications (IST'2014
Improved construction of irregular progressive edge-growth Tanner graphs
The progressive edge-growth algorithm is a well-known procedure to construct
regular and irregular low-density parity-check codes. In this paper, we propose
a modification of the original algorithm that improves the performance of these
codes in the waterfall region when constructing codes complying with both,
check and symbol node degree distributions. The proposed algorithm is thus
interesting if a family of irregular codes with a complex check node degree
distribution is used.Comment: 3 pages, 3 figure
Non-Binary LDPC Codes with Large Alphabet Size
We study LDPC codes for the channel with input and
output . The aim of this paper is to evaluate
decoding performance of -ary non-binary LDPC codes for large . We give
density evolution and decoding performance evaluation for regular non-binary
LDPC codes and spatially-coupled (SC) codes. We show the regular codes do not
achieve the capacity of the channel while SC codes do
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