Abstract
The satellite communication (Satcom) community is exploring the license-free optical spectrum to support the growing traffic demand in a cost-effective manner. However, free-space optical (FSO) communications are vulnerable to atmospheric turbulence, pointing errors, and weather effects. Space-air-ground (SAG) FSO transmission and hybrid single-hop (SH) FSO/radio frequency (RF) transmission are promising solutions to improve the performance of FSO links and can be integrated into a Satcom system. In this work, we carry out a thorough error rate analysis of the resulting integrated SAG-FSO/SH-FSO/RF Satcom system, where Gamma-Gamma and Rician distributions are used to characterize FSO and RF links, respectively. The exact analytical expressions are derived and validated by Monte-Carlo simulations. The numerical results highlight the significant potential of the integrated SAG-FSO/SH-FSO/RF Satcom system over existing solutions.