An $L^2-$stability estimate for periodic nonuniform sampling in higher dimensions
Provides theoretical guarantees for nonuniform sampling in higher dimensions, relevant to signal processing and sampling theory.
The paper establishes L2-stability estimates for reconstructing multivariate bandlimited functions with disjoint spectral bands from periodic nonuniform samples, linking reconstruction to Vandermonde matrix invertibility.
We consider sampling strategies for a class of multivariate bandlimited functions $f$ that have a spectrum consisting of disjoint frequency bands. Taking advantage of the special spectral structure, we provide formulas relating $f$ to the samples $f(y), y\in X$, where $X$ is a periodic nonuniform sampling set. In this case, we show that the reconstruction can be viewed as an iterative process involving certain Vandermonde matrices, resulting in a link between the invertibility of these matrices to the existence of certain sampling sets that guarantee a unique recovery. Furthermore, estimates of inverse Vandermonde matrices are used to provide explicit $L^{2}$-stability estimates for the reconstruction of this class of functions.