On the constructions of constant-weight codes

Two methods of constructing binary constant-weight codes from (1) codes over GF(q) and (2) constant-weight codes over GF(q) are presented. Several classes of binary optimum constant-weight codes are derived from these methods. In general, we show that binary optimum constant-weight codes, which achieve the Johnson bound, can be constructed from optimum codes over GF(q) which achieve the Plotkin bound. Finally, several classes of optimum constant-weight codes over GF(q) are constructed.