The Levenshtein’s Sequence Reconstruction Problem and the Length of the List




Junnila, Ville; Laihonen, Tero; Lehtilä, Tuomo

PublisherInstitute of Electrical and Electronics Engineers Inc.

2024

 IEEE Transactions on Information Theory

IEEE Transactions on Information Theory

70

2

1050

1066

1557-9654

DOIhttps://doi.org/10.1109/TIT.2023.3318354

https://ieeexplore.ieee.org/document/10261297

https://research.utu.fi/converis/portal/detail/Publication/181481576



In the paper, the Levenshtein’s sequence reconstruction problem is considered in the case where the transmitted words are chosen from an e -error-correcting code, at most t substitution errors occur in each of the N channels and the decoder outputs a list of length L . Previously, when t = e + ℓ and the transmitted word is long enough, the numbers of required channels were determined for L = 1, 2 and ℓ+1. Here we determine the exact number of channels in the cases L = 3,4,..., ℓ. This also provides the size of the largest intersection of L balls of radius t (with respect to substitutions) centered at the words with mutual Hamming distances at least 2 e + 1. Furthermore, with the aid of covering codes, we also consider the list sizes in the cases where the length n is rather small (improving previously known results). After that we study how much we can decrease the number of required channels when we use list-decoding codes. Finally, the majority algorithm is discussed for decoding in a probabilistic set-up; in particular, we show that the output word of the decoder can be verified to be the transmitted one with high probability.


Last updated on 28/01/2026 03:58:46 PM