It is known that in the absence of distortion, the minimum average sampling density for a multiband signal is given by its spectral occupancy [1]. Furthermore, there exist nonuniform sampling patterns of the same average sampling density such that reconstruction is feasible even if the actual spectral support of the multiband signal is unknown [2]. This is called spectrum-blind nonuniform sampling. However, if the samples are distorted, an increased sampling density may lead to superior reconstruction.
Martin Vetterli, Thierry Blu, Hanjie Pan
Michaël Unser, John Paul Ward, Hagay Kirshner