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Ensemble Weight Enumerators for Protograph LDPC CodesRecently LDPC codes with projected graph, or protograph structures have been proposed. In this paper, finite length ensemble weight enumerators for LDPC codes with protograph structures are obtained. Asymptotic results are derived as the block size goes to infinity. In particular we are interested in obtaining ensemble average weight enumerators for protograph LDPC codes which have minimum distance that grows linearly with block size. As with irregular ensembles, linear minimum distance property is sensitive to the proportion of degree-2 variable nodes. In this paper the derived results on ensemble weight enumerators show that linear minimum distance condition on degree distribution of unstructured irregular LDPC codes is a sufficient but not a necessary condition for protograph LDPC codes.
Document ID
20070023651
Document Type
Preprint (Draft being sent to journal)
External Source(s)
Authors
Divsalar, Dariush (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
August 23, 2013
Publication Date
July 9, 2006
Subject Category
Computer Systems
Meeting Information
IEEE International Symposium on Information Theory(Seattle, WA)
Distribution Limits
Public
Copyright
Other
Keywords
enumerators
low-density parity-check (LDPC)