Nonexistence of perfect permutation codes under the Kendall $$\tau $$-metric

Autor: Xiang Wang, Fang-Wei Fu, Yuanjie Wang, Wenjuan Yin
Rok vydání: 2021
Předmět:
Zdroj: Designs, Codes and Cryptography. 89:2511-2531
ISSN: 1573-7586
0925-1022
DOI: 10.1007/s10623-021-00934-z
Popis: In the rank modulation scheme for flash memories, permutation codes have been studied. In this paper, we study perfect permutation codes in $$S_n$$ , the set of all permutations on n elements, under the Kendall $$\tau $$ -metric. We answer one open problem proposed by Buzaglo and Etzion. That is, proving the nonexistence of perfect codes in $$S_n$$ , under the Kendall $$\tau $$ -metric, for more values of n. Specifically, we present the polynomial representation of the size of a ball in $$S_n$$ under the Kendall $$\tau $$ -metric for some radius r, and obtain some sufficient conditions of the nonexistence of perfect permutation codes. Further, we prove that there does not exist a perfect t-error-correcting code in $$S_n$$ under the Kendall $$\tau $$ -metric for some n and $$t=2,3,4,5,~\text {or}~\frac{5}{8}\left( {\begin{array}{c}n\\ 2\end{array}}\right) < 2t+1\le \left( {\begin{array}{c}n\\ 2\end{array}}\right) $$ .
Databáze: OpenAIRE