Steerable reflector-assisted communication in obstructed line-of-sight FSO link with optimal mitigation of dust-induced signal fading

Abstract

This paper introduces an effective technique for bridging free-space optical (FSO) communication between end-to-end nodes with obstructed direct line-of sight (LOS) by incorporating a steerable mirror-and-lens-assisted (MLA) reflector assembly. The consistency of the proposed MLA-assisted FSO system is then experimentally evaluated and contrasted against a plane mirror (PM) reflector over a test-bed link set in a laboratory-fostered dusty environment for analyzing the system performance in terms of the received beam irradiance, received signal quality and noise-inflicted signal distortions. Furthermore, an intensity-dependent steerable MLA system is implemented to cater for the beam misalignment errors during the FSO link operation. It is observed that the proposed MLA assembly, in contrast to the PM reflector, can effectively harvest and focus the dust-induced scattered information-laden laser beam to a narrow-beam spot with intense irradiance level at the receiver aperture. Finally, the signal eye diagram is obtained for analyzing the signal quality in the presence and absence of background light. Based on the experimental study, it is apparent that the MLA reflectors not only aids in establishing a reliable direct LOS-obstructed FSO link but also effectively mitigates the dusty channel-induced beam fading effect and enhances the system immunity to noise and jitter effects.