Performance analysis of MIMO-FSO communication systems in Gamma-Gamma turbulence channels with pointing errors

In this paper, we analyze the performance of multiple-input multiple-output (MIMO) free-space optical (FSO) communication systems over Gamma-Gamma (GG) turbulence channels with pointing errors. We have assumed repetition coding across lasers at the transmitter and equal gain combining (EGC), at the receiver. Performance analysis of such system needs the statistics of the sum of GG-distributed random variables (RVs), which, here, is approximated by the α-μ distribution. Numerical results show the accuracy of the developed approximation method. Moreover, the proposed method can be applied efficiently for different channels characterized by GG turbulence, pointing error and attenuation. Based on the derived results, we have analyzed the performance of MIMO-FSO system employing EGC diversity technique considering the combined effects of turbulence-induced fading, pointing error and path loss, and investigated the effects of the different design parameters on the performance of the system.