Résumé
We consider a q-ary quasi-cyclic code C of length m' and index ', where both m and ' are relatively prime to q. If the constituents of C are cyclic codes, we show that C can also be viewed as a 2-D cyclic code of size m *l ' over Fq. If we further assume that m and ' are also coprime to each other, then we easily observe that the code C must be equivalent to a cyclic code. The last fact was proved earlier by Lim using a diff erent approach.