Statistical characteristics of free space optical systems employing transmission spatial diversity

Free space optical communication has become an attractive solution for data transmission due to its cost-effective, license-free and high bandwidth characteristics. The performance of such systems, however, is highly affected by the effects of optical turbulence. Multiple laser transmitters can be used to mitigate the turbulence fading by exploiting the advantages of spatial diversity. In this work the statistical properties of the received signal of a link employing spatial diversity was investigated. The statistical properties of the photo-current generated at the receiver - required for evaluating performance parameters like availability and bit error rate - were obtained by means of computer simulation. The results presented here can be very helpful in designing a free space optical link with spatial diversity, since they are presented in function of system configurations and impairment conditions.