More on Codes Over Finite Quotients of Polynomial Rings
Abstract
Let q=pr be a prime power, Fq be the finite field of order q and f(x) be a monic polynomial in Fq [x]. Set A:=Fq [x]/ < f(x) >. In this paper we continue the study (started by T. P. Berger and N. El Amrani) of A -codes of length l over A , i.e. A -submodules of Al. We introduce two types of unique generating sets, called type I and type II basis of divisors, for an A -code. Using this, we present a building-up construction so that one can obtain all distinct A -codes of length l, with their basis of divisors. We complete the classification for the special case l=2 and enumerate all the A -codes of length 2. As an example, we list all binary index-2 quasi-cyclic codes of lengths 16 and 32, and all ternary index-2 quasi-cyclic codes of lengths 6 and 18, which are best-known codes. © 2025 The Authors.