On Some Quaternary Self-Orthogonal Codes

This paper studies families of self-orthogonal codes over Z4. We show that the simplex codes (Type α and Type β) are self-orthogonal. We partially answer the question of Z4-linearity for the codes from projective planes of even order. A new family of self-orthogonal codes over Z4 is constructed via projective planes of odd order. Properties such as shadow codes, self-orthogonality, weight distribution, etc. are studied. Finally, some self-orthogonal codes constructed from twistulant matrices are presented.