On the symbol-pair distances of repeated-root constacyclic codes of length [formula omitted].

Let p be an odd prime, and λ be a nonzero element of the finite field F p m . The λ -constacyclic codes of length 2 p s over F p m are classified as the ideals of quotient ring F p m [ x ] 〈 x 2 p s − λ 〉 in terms of their generator polynomials. Based on these generator polynomials, the symbol-pair distances of all such λ -constacyclic codes of length 2 p s are obtained in this paper. As an application, all MDS symbol-pair constacyclic codes of length 2 p s over F p m are established, which produce many new MDS symbol-pair codes with good parameters. [ABSTRACT FROM AUTHOR]