Some new lower bounds for ternary covering codes

In [5], we studied binary codes with covering radius one via their characteristic functions. This gave us an easy way of obtaining congruence properties and of deriving interesting linear inequalities. In this paper we extend this approach to ternary covering codes. We improve on lower bounds for ternary 1-covering codes, the so-called football pool problem, when 3 does not divide n − 1. We also give new lower bounds for some covering codes with a covering radius greater than one. 1partially supported by the EC grant CHRX-CT93-0400 and the “PRC maths-info”