New Construction of $q$-ary Codes Correcting a Burst of at most $t$ Deletions
Wentu Song, Kui Cai, Tony Q. S. Quek
TL;DR
This work tackles constructing $q$-ary burst-deletion codes that correct a burst of at most $t$ deletions with near-optimal redundancy and near-linear encoding/decoding. It introduces $q$-ary pattern-dense sequences and a VT-like locator, together with syndrome-compression and a sequence-replacement encoding framework (EncDen/DecDen), to achieve a redundancy of $\log n+8\log\log n+o(\log\log n)+\gamma_{q,t}$ bits and time $O(q^{7t} n (\log n)^3)$ for encoding/decoding. A key feature is that the second redundancy term is independent of $q$ and $t$, improving upon previous $\log n+O(\log q\log\log n)$ or $\log n+O(t^2\log\log n)$ bounds. The paper also discusses potential extensions to reconstruction codes with multiple reads, implying practical relevance for DNA storage and synchronization systems.
Abstract
In this paper, for any fixed positive integers $t$ and $q>2$, we construct $q$-ary codes correcting a burst of at most $t$ deletions with redundancy $\log n+8\log\log n+o(\log\log n)+γ_{q,t}$ bits and near-linear encoding/decoding complexity, where $n$ is the message length and $γ_{q,t}$ is a constant that only depends on $q$ and $t$. In previous works there are constructions of such codes with redundancy $\log n+O(\log q\log\log n)$ bits or $\log n+O(t^2\log\log n)+O(t\log q)$. The redundancy of our new construction is independent of $q$ and $t$ in the second term.
