  For a rational prime $p\neq 2$, we compute the sequence of ramification
groups of a Galois, radical and finite extension $L/F$ where $F/\mathbb{Q}_p$
is an unramified finite extension. First, we compute it in the case where the
exponent of Gal$(L/F)$ is a power of $p$, by a Hecke's theorem and some
inductions,. Finally, we deal with the general case. For the case $p=2$, the
same method can work, provided that we make an additional hypothesis.
