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arXiv 2202.00240cs.ITmath.IT
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BSC上译码的一个判据

A Criterion for Decoding on the BSC

Anup Rao, Oscar Sprumont

AI总结:

本文提出一种证明线性码抗随机错误的方法,给出传递码重量分布的紧界,并基于Krawtchouk多项式建立译码判据,进而为传递码和Reed-Muller码获得列表译码结果,部分达到信息论最优权衡。

摘要:

我们提出了一种方法来证明线性码对随机错误具有鲁棒性。我们利用这种方法获得了传递码和Reed-Muller码的译码结果。我们给出了关于一般线性码,特别是传递线性码的三类结果。\n1) 我们给出了每个传递线性码 $C \subseteq \mathbb{F}_2^N$ 的重量分布的紧界:$\Pr_{c \in C}[|c| = αN] \leq 2^{-(1-h(α)) \mathsf{dim}(C)}$。\n2) 我们给出了一个判据,用于证明线性码 $C$ 可以在二进制对称信道上进行译码。设 $K_s(x)$ 表示 $s$ 次Krawtchouk多项式,并设 $C^\perp$ 表示 $C$ 的对偶码。我们证明,对 $\mathbb{E}_{c \in C^{\perp}}[ K_{εN}(|c|)^2]$ 的界意味着 $C$ 能从参数为 $ε$ 的二进制对称信道上的错误中恢复。较弱的界可用于通过类似方法获得列表译码结果。我们判据的一个推论是:只要 $C^\perp$ 的重量分布在 $\frac{N}{2}$ 附近的某个区间内充分接近二项分布,$C$ 就对 $ε$-错误具有鲁棒性。\n3) 我们将Krawtchouk多项式的已知估计与传递码的重量界以及Reed-Muller码的已知重量界相结合,为这两类码族获得列表译码结果。在某些情况下,我们针对Reed-Muller码的界达到了速率与列表大小之间的信息论最优权衡。

英文摘要:

We present an approach to showing that a linear code is resilient to random errors. We use this approach to obtain decoding results for both transitive codes and Reed-Muller codes. We give three kinds of results about linear codes in general, and transitive linear codes in particular. 1) We give a tight bound on the weight distribution of every transitive linear code $C \subseteq \mathbb{F}_2^N$: $\Pr_{c \in C}[|c| = αN] \leq 2^{-(1-h(α)) \mathsf{dim}(C)}$. 2) We give a criterion that certifies that a linear code $C$ can be decoded on the binary symmetric channel. Let $K_s(x)$ denote the Krawtchouk polynomial of degree $s$, and let $C^\perp$ denote the dual code of $C$. We show that bounds on $\mathbb{E}_{c \in C^{\perp}}[ K_{εN}(|c|)^2]$ imply that $C$ recovers from errors on the binary symmetric channel with parameter $ε$. Weaker bounds can be used to obtain list-decoding results using similar methods. One consequence of our criterion is that whenever the weight distribution of $C^\perp$ is sufficiently close to the binomial distribution in some interval around $\frac{N}{2}$, $C$ is resilient to $ε$-errors. 3) We combine known estimates for the Krawtchouk polynomials with our weight bound for transitive codes, and with known weight bounds for Reed-Muller codes, to obtain list-decoding results for both these families of codes. In some regimes, our bounds for Reed-Muller codes achieve the information-theoretic optimal trade-off between rate and list size.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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