Performance Analysis of Coherent FSO System with SSC Receiver

Abstract

This paper analyzes the performance of coherent free-space optical (FSO) system employing the switch-and-stay (SSC) dual diversity receiver. The intensity fluctuations of the optical signal are modeled by Gamma-Gamma distribution, being caused by atmospheric turbulence. In addition, pointing errors are taken into account. Novel analytical expressions for the outage probability are derived. The general scenario of unbalanced average signal-to-noise ratios (SNRs) of independent and identically distributed SSC branches is considered, which is further simplified to the balanced SNR case. The effects of various system and channel parameters are investigated and discussed.