Outage analysis of hybrid FSO/RF systems based on finite-state Markov chain modeling

In this paper, we analyze the outage probability of a hybrid free-space optical/radio-frequency (FSO/RF) communication system with soft-switching. In soft-switching approach, either one of the links or both links can be active relying on their availabilities. We first model the link selection required for soft-switching between the FSO and RF channels in different weather conditions by a finite-state Markov chain (FSMC) process. Then, based on the proposed model, we derive a closed-form outage probability expression in terms of various system and weather condition parameters. Numerical results are provided to present the outage performance under various weather conditions.