On covering radius and discrete Chebyshev polynomials (Q1360991)

The authors show that using discrete Chebyshev polynomials instead of regular ones they get an improvement on the Honkala-Litsyn-Tietäväinen bound. In a certain interval this new bound is also better than Tietäväinen's bound. Upper bounds on even-weight codes are considered as well. The improvement is based on the fact that the authors are interested in finding a polynomial with small maximum only in the integral points of a certain interval and not in the whole interval.