Frames were introduced already in 1952 by Duffin and Schaeffer in their fundamental paper [5]; they used frames as a tool in the study of nonharmonic Fourier series. Then, in 1985, as the wavelet era began, Daubechies, Grossmann, and Meyer [4] observed that frames can be used to find series expansions of functions in L2(R) which are very similar to the expansions using orthonormal bases. Frames are basis-like building blocks that span a vector space but allow in linear dependency, which is useful to reduce noise, find amesparse representations, spherical codes, compressed sensing, signal processing, wavelet analysis etc.
