PROCÉDÉ POUR DÉTERMINER LA MODIFICATION DE PARAMÈTRES POUR MODIFIER LES CARACTÉRISTIQUES OPTIQUES D'UN ÉLÉMENT OPTIQUE DE COMPENSATION DE DISTORSIONS DANS UN FAISCEAU DE COMMUNICATION OPTIQUE EN ESPACE LIBRE

摘要

A method for phase-only compensation in free-space optical links is disclosed. By way of the invention, it can be shown that a combination of an iterative approach, image processing of a single focal intensity image, and a convex optimization technique, can correct the distorted pupil phase in a wide range of turbulence conditions, and within the coherence time of the atmosphere. The proposed technique shows a simple and versatile method for pupil phase compensation that provides significant reduction in the bandwidth required for the iterations, while keeping the hardware complexity low. The attained reduction in the required bandwidth moves towards the feasibility of iterative approaches in FSOC applications. The method according to the invention allows an adaptive use of the required iterations for SNR above 30dB, which is reasonable for LEO and airborne downlink scenarios. From a point of view of a communication channel, the technique provides an overall improvement in the mean coupled power and reduction of the fading.