The OPD and PEAs are the key devices that facilitate fast and precise beam steering to mitigate the beam wandering in the FSOC system.
The statistical results show that the neural controller in a closed loop generates the accurate control signal as required to mitigate the beam wandering.
New design approach and architecture development for the implementation of the designed neural controller in the field-programmable gate array (FPGA) to mitigate the beam wandering are presented.
Therefore, designing a suitable control system for beam auto-aligning, tracking, and positioning (ATP) to mitigate the beam wandering so as to significantly improve the beam stability on the receiver plane becomes significant.
The first and most important requirement for the successful installation of FSOC is beam steering (reduction of focal spot wander) that mitigates the beam wandering (temporal distortions) [1, 16 18] which is the research component and main contribution in this work.
Two optimization models are developed and simulated by Xian Liu for continuously adjusting the transmitter power, wavelength, telescope gain to mitigate the beam LoS deviations due to building sway, and atmospheric interference.
The corresponding results are plotted in Fig. 4. As expected, the similarity constraint can effectively mitigate the beam pattern distortion resulting from the finite sample size or nonstationary interference.
The neural controller processed the beam pointing (beam location) information obtained from an opto-electronic position detector (OPD) and then generated the necessary control outputs to the fast steering mirror (FSM) to steer the beam in the counter-direction to mitigate the beam wander at the receiver station.
The radial distance of the beam centroid on the OPD is calculated with respect to (0,0 mm using Equation 8, and the corresponding histogram plot is shown in Figure 14b: in no control (blue), in control (red), and optimal value (black) which evidences that the beam steering control system mitigates the beam wandering and stabilizes the beam almost at the center of the communication detector.
In this paper, we focus on mitigating the inter-beam interference (IBI) to improve the throughput by utilizing massive multiple input and multiple output (MIMO -based MIMO -basedm beamforming.
