Nonperiodic forced overflow oscillations in digital filters

Forced overflow oscillations are investigated in a secondorder digital filter whose input sequence is nonperiodic, having been obtained by incommensurably sampling some periodic waveform. Necessary and sufficient conditions are given for the existence of nonperiodic forced overflow oscillations in the digital filter. These conditions are shown to coincide exactly with the corresponding necessary and sufficient conditions for the existence of periodic forced overflow oscillations.