Bit-Error Rate Analysis of Free Space Optical Communications with Fiber-Based Spatial Diversity Receiver System

Abstract

The error performances of fiber-based free space optical (FSO) communications over Gamma-Gamma distributed turbulence are studied for multiple apertures receiver system. Bit-error rate (BER) performances for on-off keying (OOK) modulated direct detection fiber-based free space optical communications are derived and analyzed for equal gain combining (EGC) diversity receptions. BER performances of EGC receiver system are compared with a single monolithic aperture receiver system with the same total aperture area (same average total incident optical power on the aperture surface) for fiber-based free space optical communications. All the numerical results are also verified by Monte Carlo (MC) simulations. It is found that the multiple apertures receiver system can greatly improve the system performance for fiber-based FSO communications.