On a sampling expansion with partial derivatives for functions of several variables


Saulius Norvidas




Let B p σ , 1 ≤ p < ∞, σ > 0, denote the space of all f ∈ L p (R) such that the Fourier transform of f (in the sense of distributions) vanishes outside [−σ , σ ]. The classical sampling theorem states that each f ∈ B p σ may be reconstructed exactly from its sample values at equispaced sampling points {πm/σ } m∈Z spaced by π/σ. Reconstruction is also possible from sample values at sampling points {πθ m/σ } m with certain 1 < θ ≤ 2 if we know f (θ πm/σ) and f (θ πm/σ), m ∈ Z. In this paper we present sampling series for functions of several variables. These series involves samples of functions and their partial derivatives.