The glassy phase of Gallager codes
The glassy phase of Gallager codes
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Gallager 代码的玻璃相
DOI:
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发表时间:
2001
期刊:
影响因子:
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通讯作者:
A. Montanari
中科院分区:
文献类型:
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作者:
A. Montanari
Abstract:Gallager codes are the best error-correcting codes to date. In this paper we study them by using the tools of statistical mechanics. The corresponding statistical mechanics model is a spin model on a sparse random graph. The model can be solved by elementary methods (i.e. without replicas) in a large connectivity limit. For low enough temperatures it presents a completely frozen glassy phase (qEA = 1). The same scenario is shown to hold for finite connectivities. In this case we adopt the replica approach and exhibit a one-step replica symmetry breaking order parameter. We argue that our ansatz yields the exact solution of the model. This allows us to determine the whole phase diagram and to understand the performances of Gallager codes.