Codes on fibre products of Artin-Schreier and Kummer coverings of the projective line

In this thesis, we study smooth projective absolutely irreducible curves defined over finite fields by fibre products of Artin-Schreier and Kummer coverings of the projective line. We construct some curves with many rational points defined by the fibre products of Artin-Schreier and Kummer coverings. Then, we apply Goppa construction to the curves that we have found, and obtain long linear codes with good relative parameters.