Capacity analysis of free space optical communication system under atmospheric turbulence

• DOI: 10.1007/s11082-020-2200-6
• Publication Date: 2020-01-29T12:04:00Z
• Authors: Kanchan Sharma; Surender K. Grewal
• Keywords: 0508 media and communications; 05 social sciences

In this paper, the analytical channel capacity of the free space optical (FSO) system under weak, moderate and strong turbulence is derived. The FSO channel statistics follows the log-normal distribution under weak turbulence and follows the Gamma–Gamma distribution under moderate and strong turbulence. The three generally used adaptive transmission schemes in FSO communication system are as follows (1) optimal simultaneous power and rate adaptation, (2) optimal rate adaptation with constant transmit power, and (3) truncated channel inversion with a fixed rate. The closed-form approximations for the average ergodic channel capacity for these adaptive transmission schemes under different atmospheric turbulence without any pointing error are derived. Simulation results depict the excellent agreement of the proposed analytical models with the Monte Carlo simulation.