DocumentCode :
987670
Title :
Average coset weight distributions of Gallager´s LDPC code ensemble
Author :
Wadayama, Tadashi
Author_Institution :
Dept. of Comput. Sci., Nagoya Inst. of Technol.
Volume :
51
Issue :
7
fYear :
2005
fDate :
7/1/2005 12:00:00 AM
Firstpage :
2715
Lastpage :
2721
Abstract :
In this correspondence, the average coset weight distributions of Gallager´s low-density parity-check (LDPC) code ensemble are investigated. Gallager´s LDPC code ensemble consists of regular mtimesn-LDPC matrices with column weight j and row weight k. The average coset weight distribution can be derived by enumerating the number of parity-check matrices in the ensemble satisfying certain conditions. Based on combinatorial arguments, a formula for the average coset weight distribution will be proved. From the formula, we can show some properties of the average coset weight distributions such as equivalence classes of syndromes, symmetry of the distributions, and a lower bound on coset weight
Keywords :
matrix algebra; parity check codes; Gallager´s code; LDPC; average coset weight distribution; ensemble code; low-density parity-check code; mtimesn-LDPC matrices; Books; Iterative algorithms; Iterative decoding; Iterative methods; Linear code; Maximum likelihood decoding; Maximum likelihood detection; Parity check codes; Performance analysis; Upper bound; Coset; ensemble average; low-density parity-check (LDPC) code; weight distribution;
fLanguage :
English
Journal_Title :
Information Theory, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9448
Type :
jour
DOI :
10.1109/TIT.2005.850144
Filename :
1459072
Link To Document :
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