A note on linear complementary pairs of group codes

Abstract We give a short and elementary proof of the fact that for a linear complementary pair ( C , D ) , where C and D are 2-sided ideals in a group algebra, D is uniquely determined by C and the dual code D ⊥ is permutation equivalent to C . This includes earlier results of Carlet (2018) and Guneri (2018) on n D cyclic codes which have been proved by subtle and lengthy calculations in the space of polynomials.