| Popis: |
In this work, we introduce new construction methods for self-dual codes using a Baumert–Hall array. We apply the constructions over the alphabets F 2 and F 4 + u F 4 and combine them with extension theorems and neighboring constructions. As a result, we construct 46 new extremal binary self-dual codes of length 68, 26 new best known Type II codes of length 72 and 8 new extremal Type II codes of length 80 that lead to new 3 − ( 80 , 16 , 665 ) designs. Among the new codes of length 68 are the examples of codes with the rare γ = 5 parameter in W 68 , 2 . All these new codes are tabulated in the paper. |
Full Text from ScienceDirect