Given a discrete time sample X1,...Xn from a L\'evy process
X=(Xt)t≥0 of a finite jump activity, we study the problem of
nonparametric estimation of the characteristic triplet (γ,σ2,ρ)
corresponding to the process X. Based on Fourier inversion and kernel
smoothing, we propose estimators of γ,σ2 and ρ and study
their asymptotic behaviour. The obtained results include derivation of upper
bounds on the mean square error of the estimators of γ and σ2
and an upper bound on the mean integrated square error of an estimator of
ρ.Comment: 29 page