Performance investigations on underwater optical wireless communication system using distinguished Laguerre polynomial beams for various ocean water environments

This work numerically investigates the performance of spatial division multiplexing (SDM) technique using a single spatial green laser at 532 nm to be used to transmit two user’s signals over the underwater optical wireless communication (UOWC) channel for the first time. The proposed system presents high order Laguerre polynomial modes (LP 3 0 and LP 3 1 ) with OOK-NRZ modulation scheme. The overall system capacity is transporting 40 Gb/s binary data, each a distinct beam transmits 10 Gb/s. This study offers a comprehensive investigation on the three types of water coeffiecients (scattering and absorption) such as a pure ocean (PO), costal ocean (CO), and turbid harbor (TH) environments. Log 10 (BER), quality factor, and eye plots are utilized as metrics for the system performance. The achievable findings have a great performance even at the huge attenuation losses of 0.151 m -1 , 0.339 m -1 , and 2.195 m -1 for PO, CO, and TH environments, respectively. According to the numerical results, the higher attenuation causes an additional considerable deterioration in the UOWC transmission distances, which is degraded from 180 m in PO to 85 m and 16 m for CO and TH water types, respectively. The system is superior whole prior researches of the compared underwater articles with respect to the transmission length and transmitted data rate per user. This highlights the capability of high order of LP multiplexing for improving the system capacity in the underwater transmission.