A Construction of Binary Constant-Weight Codes From Algebraic Curves Over Finite Fields

By employing the narrow ray class groups of algebraic curves, we give a construction of constant weight codes. This construction is a generalization of the one proposed by Xing. It turns out that this generalization gives an improvement on the lower bound of binary constant codes in the earlier work of Xing, while the latter one improves an earlier result of Graham and Sloane.