Elimination of overflow oscillations in fixed-point state-space digital filters using saturation arithmetic

An unconventional approach for guaranteeing the nonexistence of zero-input limit cycles in fixed-point state-space digital filters using saturation arithmetic is presented. The approach is based on a `passivity´ property associated with the multiple saturation nonlinearities. Under certain conditions, the approach specializes to the known approach based on the sector information of the nonlinearities