ON IMPORTANCE SAMPLING IN DIGITAL-COMMUNICATIONS .1. FUNDAMENTALS

We develop a simulation algorithm design strategy based on the combination of event simulation, conditional importance sampling, and asymptotically optimal biasing of Gaussian noise inputs. The utility of this approach is illustrated by presenting numerical results for a satellite channel model that includes uplink and downlink noise sources, a TWTA nonlinearity, and ISI from both uplink and downlink filtering. Our development includes an overview and comparison of various simulation design strategies, and we present some new results on the optimization of general mean translation and variance scaling biasing schemes for nonlinear systems.