On the minimum distance of a q-ary image of a q/sup m/-ary cyclic code

摘要

We discuss a lower bound on the minimum distance of a q-ary image of q/sup m/-ary cyclic code, based on its concatenated structure due to Jensen (see ibid., vol.31, no.6, p.788-93, 1985) and Seguin (see ibid., vol.41, no.2, p.387-99, 1995). An explicit estimate for the minimum distance of the outer codes, which is analogous to the BCH bound, is derived. Complete lists of the values obtained from the lower hound are given for binary images of 2/sup 5/-ary and 2/sup 6/-ary Reed-Solomon codes.