A Comparative Study of Rare-Event Simulation Methods for Outage Probability in GSC/MRC Systems under Rician Fading

Abstract: This paper explores the use of enhanced Monte-Carlo (MC) techniques to evaluate the outage probability of single-input-multiple-output (SIMO) systems under Rician fading, in which the input is combined using generalized selection combining with maximum ratio combining (GSC/MRC). The studied set of methods includes previously established methods: universal importance sampling (UIS) and multilevel splitting (MLS), alongside readapted methods: exponential twisting (ET) and cross-entropy (CE), and a novel method introduced here: partition importance sampling (PIS). Performance is assessed across standard efficiency metrics, revealing that ET, CE, and PIS exhibit the best performance. CE is found to be the most robust method among them.