MDS Symbol-Pair Repeated-Root Constacylic Codes of Prime Power Lengths Over $\mathbb F_{p^m}+ u \mathbb F_{p^m}$

MDS codes have the highest possible error-detecting and error-correcting capability among codes of given length and size. Let <inline-formula> <tex-math notation="LaTeX">$p$ </tex-math></inline-formula> be any prime, and <inline-formula> <tex-math notation="LaTeX">$s$ </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">$m$ </tex-math></inline-formula> be positive integers. Here, we consider all constacyclic codes of length <inline-formula> <tex-math notation="LaTeX">$p^{s}$ </tex-math></inline-formula> over the ring <inline-formula> <tex-math notation="LaTeX">$\mathcal R= \mathbb F_{p^{m}}+ u \mathbb F_{p^{m}}\, (u^{2}=0)$ </tex-math></inline-formula>. The units of the ring <inline-formula> <tex-math notation="LaTeX">$\mathcal R$ </tex-math></inline-formula> are of the form <inline-formula> <tex-math notation="LaTeX">$\alpha +u\beta $ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$\gamma $ </tex-math></inline-formula>, where <inline-formula> <tex-math notation="LaTeX">$\alpha, \, \beta, \, \gamma \in \mathbb F_{p^{m}}^{*}$ </tex-math></inline-formula>, which provides <inline-formula> <tex-math notation="LaTeX">$p^{m}(p^{m}-1)$ </tex-math></inline-formula> constacyclic codes. We acquire that the <inline-formula> <tex-math notation="LaTeX">$(\alpha + u \beta)$ </tex-math></inline-formula>-constacyclic codes of <inline-formula> <tex-math notation="LaTeX">$p^{s}$ </tex-math></inline-formula> length over <inline-formula> <tex-math notation="LaTeX">$\mathcal R$ </tex-math></inline-formula> are the ideals <inline-formula> <tex-math notation="LaTeX">$\langle (\alpha _{0}\,\,x - 1)^{j} \rangle $ </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">$0 \leq j \leq 2~p^{s}$ </tex-math></inline-formula>, of the finite chain ring <inline-formula> <tex-math notation="LaTeX">$R [x] / \langle x^{p^{s}} - (\alpha + u \beta) \rangle $ </tex-math></inline-formula> and the <inline-formula> <tex-math notation="LaTeX">$\gamma $ </tex-math></inline-formula>-constacyclic codes of <inline-formula> <tex-math notation="LaTeX">$p^{s}$ </tex-math></inline-formula> length over <inline-formula> <tex-math notation="LaTeX">$\mathcal R$ </tex-math></inline-formula> are the ideals of the ring <inline-formula> <tex-math notation="LaTeX">$\mathcal R[x] / \langle x^{p^{s}} - \gamma \rangle $ </tex-math></inline-formula> which is a local ring with the maximal ideal <inline-formula> <tex-math notation="LaTeX">$\langle u, x - \gamma _{0} \rangle $ </tex-math></inline-formula>, but it is not a chain ring. In this paper, we obtain all MDS symbol-pair constacyclic codes of length <inline-formula> <tex-math notation="LaTeX">$p^{s}$ </tex-math></inline-formula> over <inline-formula> <tex-math notation="LaTeX">$\mathcal R$ </tex-math></inline-formula>. We deduce that the MDS symbol-pair constacyclic codes are the trivial ideal <inline-formula> <tex-math notation="LaTeX">$\langle 1 \rangle $ </tex-math></inline-formula> and the Type 3 ideal of <inline-formula> <tex-math notation="LaTeX">$\gamma $ </tex-math></inline-formula>-constacyclic codes for some particular values of <inline-formula> <tex-math notation="LaTeX">$p$ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$s$ </tex-math></inline-formula>. We also present several parameters including the exact symbol-pair distances of MDS constacyclic symbol-pair codes for different values of <inline-formula> <tex-math notation="LaTeX">$p$ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$s$ </tex-math></inline-formula>.

[1]  S. Dougherty,et al.  Maximum Distance Separable Codes in the ρ Metric over Arbitrary Alphabets , 2002 .

[2]  James L. Massey,et al.  On Repeated-root Cyclic Codes , 1991, IEEE Trans. Inf. Theory.

[3]  Songsak Sriboonchitta,et al.  On the Symbol-Pair Distance of Repeated-Root Constacyclic Codes of Prime Power Lengths , 2018, IEEE Transactions on Information Theory.

[4]  Sergio R. López-Permouth,et al.  Cyclic and negacyclic codes over finite chain rings , 2004, IEEE Transactions on Information Theory.

[5]  Simon Litsyn,et al.  Symbol-pair codes: Algebraic constructions and asymptotic bounds , 2011, 2011 IEEE International Symposium on Information Theory Proceedings.

[6]  Hongwei Liu,et al.  On structure and distances of some classes of repeated-root constacyclic codes over Galois rings , 2017, Finite Fields Their Appl..

[7]  Bocong Chen,et al.  Constacyclic Symbol-Pair Codes: Lower Bounds and Optimal Constructions , 2016, IEEE Transactions on Information Theory.

[8]  W. Cary Huffman,et al.  Fundamentals of Error-Correcting Codes , 1975 .

[9]  Shixin Zhu,et al.  A Construction of New MDS Symbol-Pair Codes , 2015, IEEE Transactions on Information Theory.

[10]  Mario Blaum,et al.  Codes for Symbol-Pair Read Channels , 2010, IEEE Transactions on Information Theory.

[11]  Songsak Sriboonchitta,et al.  Repeated-root constacyclic codes of prime power lengths over finite chain rings , 2017, Finite Fields Their Appl..

[12]  Hai Q. Dinh,et al.  Constacyclic codes of length 2p s over F p m +uF p m . , 2016 .

[13]  Graham H. Norton,et al.  On the Hamming distance of linear codes over a finite chain ring , 2000, IEEE Trans. Inf. Theory.

[14]  Shixin Zhu,et al.  New MDS Symbol-Pair Codes From Repeated-Root Codes , 2018, IEEE Communications Letters.

[15]  Tao Zhang,et al.  Maximum Distance Separable Codes for b-Symbol Read Channels , 2016, Finite Fields Their Appl..

[16]  Yeow Meng Chee,et al.  Maximum Distance Separable Codes for Symbol-Pair Read Channels , 2012, IEEE Transactions on Information Theory.

[17]  Tao Zhang,et al.  New constructions of MDS symbol-pair codes , 2016, Des. Codes Cryptogr..

[18]  Hongwei Liu,et al.  Constacyclic codes of length 2ps over Fpm+uFpm , 2016, Finite Fields Their Appl..

[19]  Gennian Ge,et al.  Constructions of maximum distance separable symbol-pair codes using cyclic and constacyclic codes , 2017, Des. Codes Cryptogr..

[20]  F. MacWilliams,et al.  The Theory of Error-Correcting Codes , 1977 .