Author_Institution :
Dept. of Math., Indian Inst. of Technol., Kanpur, India
Abstract :
Two strongly seminormal codes over Z5 are constructed to prove a conjecture of Ostergard (see ibid., vol.37, no.3, p.660-4, 1991). It is shown that a result of Honkala (see ibid., vol.37, no.4, p.1203-6, 1991) on (k,t)-subnormal codes holds also under weaker assumptions. A lower bound and an upper bound on Kq(n, R), the minimal cardinality of a q-ary code of length n with covering radius R are obtained. These give improvements in seven upper bounds and twelve lower bounds by Ostergard for Kq(n, R) for q=3, 4, and 5
Keywords :
linear codes; (k,t)-subnormal codes; covering radius; lower bound; minimal cardinality; q-ary covering codes; strongly seminormal codes; upper bound; Error correction codes; Galois fields; Helium; Mathematics; Upper bound;
