Accelerated iterative band-limited extrapolation algorithms

The iterative algorithms of Papoulis-Gerchberg and Cadzow are well-known algorithms for solving the band-limited extrapolation problem. These algorithms, however, are usually slowly convergent. We propose an acceleration scheme for both algorithms, based on finding best approximation in appropriate subspaces. The acceleration scheme can also be applied to other cases of signal restoration, which admit Youla's method of alternating orthogonal projections.