Analysis of Overlap in Waveform Relaxation Methods for RC Circuits

Waveform relaxation (WR) methods are based on partitioning large circuits into sub-circuits which can be solved separately, and an iteration using transmission conditions then leads to better and better approximations of the entire circuit. Optimized waveform relaxation (OWR) methods work similarly, but they use more effective transmission conditions between sub-circuits. We study here for the first time the influence of overlap on WR and OWR applied to RC circuits. We derive an optimization problem which characterizes the best choice of certain resistance parameters in the transmission conditions for convergence, and give an asymptotic solution of this optimization problem. We also illustrate our results with numerical experiments.