Outage performance and diversity gain analysis of free-space optical multi-hop parallel relaying

In this paper, we investigate the outage performance of free-space optical mesh networks, which build upon the combination of serial (multi-hop) and parallel relaying. We assume log-normal atmospheric turbulence channels and derive outage probability expressions for the multi-hop parallel relaying scheme under consideration. Our outage probability analysis demonstrates substantial performance improvements with respect to both standalone serial and parallel relaying schemes. Furthermore, we present a diversity gain analysis and quantify the achievable diversity order in terms of the number of relays and the turbulence channel parameters.