Constant-List Insertion--Deletion Codes:New Bounds and an Improvement of Levenshtein's Lower Bound
We study codes correcting adversarial insertions and deletions with list size $L$ fixed independently of the block length. We derive new achievable-rate bounds for binary codes and upper bounds over every fixed alphabet of size $q\ge2$, retaining explicit dependence on $L$. We establish a combinatorial reduction that t...