Summary

2020

Session Number:B06

Session:

Number:B06-2

Optimal Reconstruction Codes for Deletion Channels

Johan Chrisnata,  Han Mao Kiah,  Eitan Yaakobi,  

pp.279-283

Publication Date:2020/10/18

Online ISSN:2188-5079

DOI:10.34385/proc.65.B06-2

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Summary:
The sequence reconstruction problem, introduced by Levenshtein in 2001, considers a communication scenario where the sender transmits a codeword from some codebook and the receiver obtains multiple noisy reads of the codeword.
Motivated by modern storage devices, we introduced a variant of the
problem where the number of noisy reads \(N\) is fixed (Kiah et al. 2020).
Of significance, for the single-deletion channel,
using \(\log_2\log_2 n +O(1)\) redundant bits, we designed a codebook of length \(n\) that reconstructs codewords from two distinct noisy reads.

In this work, we show that \(\log_2\log_2 n -O(1)\) redundant bits are necessary for such reconstruction codes,
thereby, demonstrating the optimality of our previous construction.
Furthermore, we show that these reconstruction codes can be used in \(t\)-deletion channels (with \(t\ge 2\)) to uniquely reconstruct codewords from \(n^{t-1}+O\left(n^{t-2}\right)\) distinct noisy reads.