In this paper, we study the structure of cyclic, quasi-cyclic, constacyclic codes and their skew codes over the finite ring R = Z3+vZ3+v 2 Z3, v 3 = v. The Gray images of cyclic, quasi-cyclic, skew cyclic, skew quasicyclic and skew constacyclic codes over R are obtained. A necessary and sufficient condition for cyclic (negacyclic) codes over R that contains its dual has been given. The paramete...

Abstract In this paper some good quasi-cyclic codes over GF(3) are presented. These quasi-cyclic codes improve the already known lower bounds on the minimum distance of the previously known quasi-cyclic codes. Even though these codes do not improve the minimum distance of the best unstructured code known, their beautiful structure and simplicity provide several advantages in comparison to other...

In this article we present a new class of modules which is named as principally -lifting modules. This termed by Principally in work defined as, module called if for every cyclic submodule with , there decomposition such that and g-small . Thus, ring it -module. We determined structure. Several characterizations, properties, instances are described these modules'.

We mainly investigate the structures of skew cyclic and skew quasicyclic codes of arbitrary length over Galois rings. Similar to [5], our results show that the skew cyclic codes are equivalent to either cyclic and quasi-cyclic codes over Galois rings. Moreover, we give a necessary and sufficient condition for skew cyclic codes over Galois rings to be free. A sufficient condition for 1-generator...

This paper considers the equivalence problem for quasi-cyclic codes over finite fields. The results obtained are used to construct isodual quasi-cyclic codes.

We study the codes of title by CRT method, that decomposes such into constituent codes, which are shorter over larger alphabets. Criteria on these for self-duality and linear complementary duality decomposed derived. The special class one-generator is given a polynomial representation exactly enumerated. In particular, we present some illustrative examples binary optimal with respect to Griesme...

There is a one-to-one correspondence between l-quasi-cyclic codes over a finite field Fq and linear codes over a ring R = Fq[Y ]/(Y m − 1). Using this correspondence, we prove that every l-quasi-cyclic self-dual code of length ml over a finite field Fq can be obtained by the building-up construction, provided that char (Fq) = 2 or q ≡ 1 (mod 4), m is a prime p, and q is a primitive element of F...

This paper is concerned with construction and structural analysis of both cyclic and quasi-cyclic codes, particularly LDPC codes. It consists of three parts. The first part shows that a cyclic code given by a parity-check matrix in circulant form can be decomposed into descendant cyclic and quasi-cyclic codes of various lengths and rates. Some fundamental structural properties of these descenda...