On the application of Cadzow´s extrapolation method of BL signals

The algorithm proposed by J.A. Cadzow (1979) for the extrapolation of a time-truncated version of a band-limited (BL) signal (this algorithm is known as a one-step extrapolation procedure) is considered. It is shown that this continuous algorithm can be applied only in cases in which the Fourier transform of the BL signal can be considered as a segment of a Fourier transform of a time-limited signal. It is also shown that the meaning of the above leads to severe restrictions on the class of signals that can be extrapolated by the continuous algorithm, as well as to its ultimate sensitivity to the exact knowledge of the bandwidth of the sought signal. These restrictions do not apply to the numerical version, which always has a solution and, in most cases, a satisfactory one