New quaternary linear codes with covering radius 2

A new quaternary linear code of length 19, codimension 5, and covering radi us 2 is found in a computer search using tabu search, a local search heuris tic. Starting from this code, which has some useful partitioning properties , different lengthening constructions are applied to get an infinite family of new, record-breaking quaternary codes of covering radius 2 and odd codi mension. An algebraic construction of covering codes over alphabets of even characteristic is also given. (C) 2000 Academic Press.