An orbital angular momentum incorporated UWOC system employing WMZCC and DPS codes under pure sea, clear ocean and coastal sea

Abstract The adoption of twisted light beams and optical code division multiplexing (OCDMA) in underwater wireless optical communication (UWOC) represents a significant step forward in underwater communication technology, offering new possibilities for secure and high-speed data transfer in challenging underwater environments. A weight managed zero cross correlation (WMZCC) code-based UWOC system is demonstrated, capable of providing four users with a 10 Gbps capacity in various ocean/sea conditions, including coastal, clear and pure seas. The WMZCC code is having lower code lengths, mapping free user generation, least multiple access interference (MAI) and easy to generate code matrix. By using the Q factor as an assessment criteria, the performance comparisons between OAM-WMZCC codes and OAM diagonal permutation shift (DPS) has been established. The findings show that OAM-WMZCC performs better than OAM-DPS because of the ZCC code and DPS has variable cross correlation. Further, it is also observed that OAM beam Laguerre–Gaussian (LG) 0,0 offered highest Q factor due to least mode diameter and LG 90,0 provide least performance because of maximum energy leakage at receiver. In comparison to OAM-DPS codes in UWOC, the presented OAM-WMZCC codes provide Q factor enhancements of 28 %, and without using OAM in the system, the presented system surpassed the performance of DPS codes by 21 %.