Constructing Permutation Codes Under the Generalized Kendall- \(\tau \) Metric
摘要
Permutation codes under the generalized Kendall- \(\tau \) metric are error-correcting codes with applications in rank modulation and related storage systems. Constructing permutation arrays is a challenging problem since even computing the distance between two permutations is NP-hard. This paper investigates (n, d)-permutation arrays (PAs) with prescribed length of permutations n and minimum generalized Kendall- \(\tau \) distance d. We determine exact values of T(n, d), the maximum size of a PA, for \(n=4\) and \(d=2,3\) . We develop algorithms for computing Kendall– \(\tau \) distances and constructing permutation arrays for \(n \le 11\) . An efficient testing procedure for (n, 2)-PAs is also presented.