1990/01/01 by J.H. Conway, John H. Conway, N. J. A. Sloane +1 · 13 citations
Computer Science · Engineering · Mathematics · #Coding theory and cryptography #graph theory and CDMA systems #Finite Group Theory Research
paper · doi:10.1109/18.59931
It is shown that the minimal distance d of a binary self-dual code of length n>or=74 is at most 2((n+6)/10). This bound is a consequence of some new conditions on the weight enumerator of a self-dual code obtained by considering a particular translate of the code, called its shadow. These conditions also enable one to find the highest possible minimal distance of a self-dual code for all n>or=60; to show that self-dual codes with d<or=6 exist precisely for n>or=22, with d>or=8 exist precisely for n=24, 32 and n>or=26, and with d>or=10 exist precisely for n>or=46; and to show that there are exactly eight self-dual codes of length 32 with d=8. Several of the self-dual codes of length 34 have trivial group (this appears to be the smallest length where this can happen).<<ETX>>