Comments on "Sinc interpolation of discrete periodic signals"

In a recent paper by T. Schanze (see ibid., vol.43, p.1502-3, 1995) the convolution of the sinc kernel with the infinite sequence of a periodic function was expressed as a finite summation. The expression obtained, however, is not numerically stable when evaluated at or near integer values of time. This correspondence presents a numerically stable formulation that is equivalent to the results reported in the above-cited paper and that, when sampled, is also shown to be equivalent to the inverse discrete Fourier transform (IDFT).