Performance Analysis of Passive Retro-Reflector Based Tracking in Free-Space Optical Communications With Pointing Errors

Abstract

In this correspondence, we propose a diversityachieving retroreflector-based fine tracking system for free-space optical (FSO) communications. We show that multiple retroreflectors deployed around the communication telescope at the aerial vehicle save the payload capacity and enhance the outage performance of the fine tracking system. Through the analysis of the joint-pointing loss of the multiple retroreflectors, we derive the ordered moments of the received power. Our analysis can be further utilized for studies on multiple input multiple output (MIMO)-FSO. After the moment-based estimation of the received power distribution, we numerically analyze the outage performance. The greatest challenge of retroreflector-based FSO communication is a significant decrease in power. Still, our selected numerical results show that, from an outage perspective, the proposed method can surpass conventional methods.

Performance Analysis of MRR Array for UAV-based FSO Links

“…According to the distance between the MRRs, the coefficients h a1m s are independent of each other. On the other hands, since the reflected path is completely consistent with the GU link, based on the results of [5], the coefficients of h a1m and h a2m are correlated and therefore, using (8), the PDF of h am = h a1m h a2m is obtained as:…”

“…In the MRR-based topology, complexity and tracking equipment are transferred from the UAV node to the ground station (GS). In addition, the signal reflected from the MRR can be used in the tracking system of the GS [5]. Even though MRR-based optical wireless communications have been well studied in the context of underwater optical wireless communications [4], this subject is limited to few works in the context of UAV-based FSO communications [6]- [10].…”