Linear codes over F
p often admit a natural
representation as trace codes of codes that are defined over an
extension field F
pm. In the paper, the authors obtain
estimates for the weights of subcodes of such trace codes. Their main
result is a far-reaching generalization of the Carlitz-Uchiyama bound
for the duals of binary BCH codes. In particular, they prove sharp
bounds
... [Show full abstract] for the generalized Hamming weights of a large class of codes,
including duals of BCH codes, classical Goppa codes, Melas codes, and
arbitrary cyclic codes of length n=pm-1. The main tool is the
theory of algebraic functions over finite fields, in particular the
Hasse-Weil bound for the number of places of degree one