On Universal LDPC Code Ensembles Over Memoryless Symmetric Channels
On Universal LDPC Code Ensembles Over Memoryless Symmetric Channels
复制标题
无记忆对称信道上的通用 LDPC 码集成
DOI:
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发表时间:
2011
影响因子:
2.5
通讯作者:
Boaz Shuval
中科院分区:
文献类型:
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作者:
I. Sason;Boaz Shuval
A design of robust error-correcting codes that achieve reliable communication over various channels is of great theoretical and practical interest. Such codes are termed universal. This paper considers the universality of low-density parity-check (LDPC) code ensembles over families of memoryless binary-input output-symmetric (MBIOS) channels. Universality is considered both under belief-propagation (BP) and maximum-likelihood (ML) decoding. For the BP decoding case, we derive a density-evolution-based analytical method for designing LDPC code ensembles that are universal over various families of MBIOS channels. We also derive a necessary condition for universality of LDPC code ensembles under BP decoding; this condition is used to provide bounds on the universally achievable fraction of capacity. These results enable us to provide conditions for reliable/unreliable communications under BP decoding that are based on the Bhattacharyya parameter of the channel. For the ML decoding case, we prove that properly selected regular LDPC code ensembles are universally capacity-achieving for the set of equi-capacity MBIOS channels and extend this result to punctured regular LDPC code ensembles.