Multirate signal reconstruction and filter design via sampled-data control

This paper studies the problem of digital signal reconstruction in the multirate framework. In contrast to the typical digital domain formulation in the current digital signal processing, we present a solution that optimizes an analog performance, via the modern sampled-data control. While the standard technique often indicates that an ideal digital low-pass filter is preferred, we show that the optimal solution need not be an ideal low-pass when the signal is not completely band-limited. The present method also suggests a new filter design method without recourse to analog filter designs. A design example is presented to show the advantages of the present method.