Secrecy Performance Enhancement of Artificial Noise Injection Scheme-based FSO Systems

Artificial noise (AN) injection is one of the promising techniques for improving the secrecy performance of a communication system. In this paper, AN injection scheme is incorporated in free-space optical (FSO) communication system for improving the secrecy performance of free-space optical (FSO) communication systems. The FSO link is subjected to Gamma-Gamma (GG) distributed atmospheric turbulence (AT) with pointing errors (PEs). It is assumed that legitimate transmitter has only one FSO aperture while the legitimate receiver as well as an eavesdropper are equipped with multiple FSO apertures. The performance of the considered system is investigated by deriving novel series-based expressions for secrecy outage probability (SOP), secrecy throughput, and strictly positive secrecy capacity (SPSC) of the system. Finally, through numerical results, it is shown that the number of FSO apertures along with the proposed AN injection scheme and GG distributed AT with PEs have a significant impact on the performance of the considered system.