Performance analysis of hybrid free space optical and visible light communications for underwater applications using spatial diversity

Abstract In this paper, we analyze a combination based on hybrid triple hop terrestrial free-space optical (FSO), fiber optic cable (FOC), and an underwater wireless communication (UOWC) link for providing high-speed connectivity between onshore submerge systems. UOWC, scattering, absorption, turbulence severely degrade the reliability transmission rate of UOWC link. our manuscript, bend-insensitive intermediate FOC spatial diversity (SD) are exploited to improve error performance links, which involves deployment multiple input single outputs (MISO). For purpose, different signaling schemes, such as pulse position modulation (PPM) with (SM) on–off keying (OOK) repetition coding (RC), employed evaluate system in terms average bit (ABER). The behavior entire is obtained by applying decode-and-forward (DF), where consider log-normal channels FSO UOWC. path loss using intensity direct detection schemes. To obtain results, Monte Carlo-based statistical simulation method applied validate analytical ABER system. achieved results reveal that MISO-OOK-RC has superior compared MISO-PPM-SM higher signal-to-noise ratio (SNR) conditions strengths.