Outage performance of MIMO free-space optical systems in gamma-gamma fading channels

In this paper, we consider a MIMO Free-Space Optical (FSO) communication system over gamma-gamma turbulence channels and derive a closed-form analytical expression for the outage probability taking into account the effects of both the inner scale size of optical channel and the aperture averaging. Our results demonstrate that by increasing the number of transmit and/or receive apertures, the degrading effect of the inner scale size is effectively reduced by extracting the spatial diversity gain of the MIMO scheme. We further provide Monte Carlo simulation results to confirm the validity of the derived expression.