Reduction of the beam pointing error for improved free-space optical communication link performance

Free-space optical communication is emerging as a low-power, low-cost, and high data rate alternative to radio-frequency in short- medium-range applications. However, it requires close-to-line-of-sight link between the transmitter receiver. This paper proposes robust H∞ control law for free-space (FSO) beam pointing error systems under controlled weak turbulence conditions. The objective maintain transmitter–receiver line, which means center of close possible receiving aperture within prescribed disturbance attenuation level. First, we derive an augmented nonlinear discrete-time model loss due misalignment caused by atmospheric turbulence. We then investigate H∞-norm optimization problem that guarantees closed-loop stable ensures attenuation. Furthermore, evaluate outage probability bit (BER) quantify performance fading channels. Finally, concludes with numerical simulation proposed approach FSO link’s performance.