The covering radius of extremal self-dual code D11 and its application
D11, constructed by Conway and Sloane, is an extremal self-dual [56, 28, 12]-code with weight enumerator 1 + 8190y(12) + 622314y(16) + 11699688y(20) +.... We find that the covering radius of D11 is 10. This shows that the inequality R(C-56) less than or equal to 10 in [1] cannot be improved any more, where R(C-56) is the covering radius of any extremal doubly even [56, 28, 12]-code C-56 And we use it to get ten new [58, 29, 10]-codes.
covering radius self-dual codes weight enumerator