Robust Power Allocation in Optical Satellite MIMO Links With Pointing Jitter

Abstract

In this letter, an optical satellite system is considered comprised of a geostationary satellite with multiple transmitters on-board and an optical ground station with multiple receiving telescopes. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathbf {\mathrm {A}}$ </tex-math></inline-formula> robust power allocation strategy for the downlink is investigated incorporating the effects of the atmospheric impairments as well as the optical beam pointing jitter. Firstly, a theoretical analysis for the optical satellite system under pointing jitter is given and a maximin optimization problem is formulated maximizing the worst-case network capacity. The power allocation is carried out under peak and total power constraints using standard convex techniques. The lower bound of the ergodic network capacity for independent log-normal optical channels over variable jitter variance is derived. The proposed methodologies are evaluated via simulations using experimental channel measurements from the ARTEMIS-optical satellite campaign and their performances are compared to baseline power allocation strategies. The presented results show the effects of jitter on the network capacity and confirm the superiority of the proposed allocation scheme.