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arXiv 1507.06175cs.ITcs.DMcs.DSmath.IT
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一种有效的纠正多删除的低冗余码

Efficient Low-Redundancy Codes for Correcting Multiple Deletions

Joshua Brakensiek, Venkatesan Guruswami, Samuel Zbarsky

摘要:

我们考虑的问题,构建二进制码恢复$k$位删除与有效的编码/解码,对于一个固定的$k$。单缺失的情况是很好理解的,1965年的Varshamov-Tenengolts-Levenshtein代码给出了具有长度为$n$的$\approx 2^n/n$码字的渐近最佳构造,即,至多$\log n$位冗余。然而,即使对于两个缺失的情况,也没有已知的具有小于$n^{Ω(1)}$的冗余的显式构造。对于任何固定的$k$,我们构建了一个二进制码与$c_k \log n$冗余,可以从$k$删除在$O_k(n \log^4 n)$时间解码。系数$c_k$可以取为$O(k^2 \log k)$,其仅比$O(k)$的最优非构造性界限差二次方。我们还指出如何修改此代码,以允许组合多达$k$插入和删除。

英文摘要:

We consider the problem of constructing binary codes to recover from $k$-bit deletions with efficient encoding/decoding, for a fixed $k$. The single deletion case is well understood, with the Varshamov-Tenengolts-Levenshtein code from 1965 giving an asymptotically optimal construction with $\approx 2^n/n$ codewords of length $n$, i.e., at most $\log n$ bits of redundancy. However, even for the case of two deletions, there was no known explicit construction with redundancy less than $n^{Ω(1)}$. For any fixed $k$, we construct a binary code with $c_k \log n$ redundancy that can be decoded from $k$ deletions in $O_k(n \log^4 n)$ time. The coefficient $c_k$ can be taken to be $O(k^2 \log k)$, which is only quadratically worse than the optimal, non-constructive bound of $O(k)$. We also indicate how to modify this code to allow for a combination of up to $k$ insertions and deletions.

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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