Error Bound and Implementation of a Simplified Causality Assessment Method

Time domain simulation of channel transfer functions sometimes results in fatal error due to causality violation. To address this issue, despersion relation with subtractions (DRwS) has been introduced. In this work, we propose formulation and implementation detail for the case of zero subtractions, which is not a special case of DRwS and the results thus complement the knowledge in the literature. Test cases show that the formulation is correct, and the consideration of singularity is crucial to the correct detection of noncausality.