Terrestrial free space line of sight optical communication (TFSLSOC) using adaptive control steering system with laser beam Tracking, Aligning and Positioning (ATP)

Free space optical communication (FSOC) is the most promising approach for addressing the emerging broadband access network. Quick link setup, high transmission security, large bandwidth and light weight are some of the important features of this system. However, the laser power attenuation due to adverse weather conditions and scattering due to turbulence are to be mitigated. In this paper, a position sensing detector (PSD) and stochastic parallel gradient descent algorithm (SPGDA) based control system using field programmable gate array (FPGA) in a closed loop control configuration (CLCC) are developed and presented for aligning, tracking and positioning (ATP) the laser beam to improve the performance of the FSOC.