Impact of Temporary Link Blockage on Ergodic Capacity of FSO System

Abstract

Free‐space optical (FSO) systems have attracted much attention from both research and application perspectives owing to their many benefits, such as license‐free operation, low‐cost, and high data rates. This paper investigates the ergodic capacity of FSO systems, which is an important metric of system performance. The stochastic temporary laser‐beam blockage, pointing errors, and atmospheric turbulence are simultaneously considered. The results illustrate that the link blockage causes a decreased ergodic capacity. We show that to maximize the ergodic capacity, there is an optimal value of the laser‐beam radius at the waist, which largely depends on pointing errors; however, it is independent of the atmospheric turbulence and the probability of link blockage.

Keywords

• Atmospheric turbulence
• Ergodic capacity
• Free‐space optical (FSO) communications
• Pointing errors
• Temporary link blockage