Efficient sampling of band-limited signals from sine wave crossings

This correspondence presents an efficient method for reconstructing a band-limited signal in the discrete domain from its crossings with a sine wave. The method makes it possible to design A/D converters that only deliver the crossing timings, which are then used to interpolate the input signal at arbitrary instants. Potentially, it may allow for reductions in power consumption and complexity in these converters. The reconstruction in the discrete domain is based on a recently-proposed modification of the Lagrange interpolator, which is readily implementable with linear complexity and efficiently, given that it re-uses known schemes for variable fractional-delay (VFD) filters. As a spin-off, the method allows one to perform spectral analysis from sine wave crossings with the complexity of the FFT. Finally, the results in the correspondence are validated in several numerical examples.

This work has been supported by the Spanish Ministry of Education and Science (MEC), Generalitat Valenciana (GV), and by the University of Alicante (UA) under the following projects/programmes: TEC2005-06863-C02-02, HA2007-075 and “Ramón y Cajal” (MEC); ACOMP07-087 and GV07/214 (GV); and GRE074P (UA).