Modeling and Design of IRS-Assisted Multilink FSO Systems

In this paper, we investigate the modeling and design of intelligent reflecting surface (IRS)-assisted optical communication systems, which can circumvent line-of-sight (LOS) requirement in multi-link free space (FSO) systems. The FSO laser beams incident on IRSs have a Gaussian power intensity profile nonlinear phase profile, whereas plane waves radio frequency (RF) systems uniform linear profile. Given these substantial differences, results available for IRS-assisted RF are not applicable to Therefore, develop new analytical channel model point-to-point based Huygens-Fresnel principle. Our captures impact size, position, orientation IRS as well its shift end-to-end channel. To allow sharing by multiple links, propose three different protocols, namely time division (TD), IRS-division (IRSD), homogenization (IRSH) protocols. proposed protocols address specific characteristics including non-uniformity possible misalignment beams. Furthermore, compare analyze bit error rate (BER) outage probability presence inter-link interference. simulation validate accuracy confirm that is both large intermediate IRS-receiver lens distances. show IRSD IRSH interference becomes negligible if properly centered transceivers carefully positioned, respectively. Moreover, absence errors, protocol outperforms other performs significantly better than protocol.