40 research outputs found
The Permutation Groups and the Equivalence of Cyclic and Quasi-Cyclic Codes
We give the class of finite groups which arise as the permutation groups of
cyclic codes over finite fields. Furthermore, we extend the results of Brand
and Huffman et al. and we find the properties of the set of permutations by
which two cyclic codes of length p^r can be equivalent. We also find the set of
permutations by which two quasi-cyclic codes can be equivalent
Some Constacyclic Codes over Finite Chain Rings
For an -th power of a unit in a finite chain ring we prove that
-constacyclic repeated-root codes over some finite chain rings are
equivalent to cyclic codes. This allows us to simplify the structure of some
constacylic codes. We also study the -constacyclic codes of
length over the Galois ring