# Shadow Bounds for Self-Dual Codes

@article{Rains1998ShadowBF, title={Shadow Bounds for Self-Dual Codes}, author={Eric M. Rains}, journal={IEEE Trans. Inf. Theory}, year={1998}, volume={44}, pages={134-139} }

Conway and Sloane (1990) have previously given an upper bound on the minimum distance of a singly-even self-dual binary code, using the concept of the shadow of a self-dual code. We improve their bound, finding that the minimum distance of a self-dual binary code of length n is at most 4[n/24]+4, except when n mod 24=22, when the bound is 4[n/24]+6. We also show that a code of length a multiple of 24 meeting the bound cannot be singly-even. The same technique gives similar results for additive…

## 236 Citations

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