OCDMA transmission-based underwater wireless optical communication system: performance analysis

Abstract

This paper introduces a novel underwater (UW) optical communication system that utilizes optical code division multiple access transmission technique using the permutation vector code. Three scenarios of water are considered, pure sea (PS), clear ocean (CL), and coastal ocean (CO). The performance is evaluated analytically in terms of bit error rate (BER), received power, signal to noise ratio for different UW links and data rates. The results show that the shortest UW range is achieved in the case of CO, achieving the highest extinction ratio compared to CL and PS. Considering a BER below the forward error correction (FEC) limit of 3 × $${10}^{-3}$$ 10 - 3 , the maximum UW ranges reached are 21 m for PS, 12 m for CL, and 8 m for CO at 3 Gbps with 20 dBm transmitted power. The propagation range could be increased when the transmitted power is increased to 25 dBm, achieving the ranges of 31 m, 18 m, and 9 m, for PS, CL, and CO, respectively.

Error Characterization of Differential Detection and Non-Differential Detection for MIMO UWOC Systems in Seawater Turbulent Channels

“…The development of devices, such as marine environmental monitors, underwater highresolution imaging systems, and autonomous underwater vehicles (AUVs), has increased the need for real-time communication and high-capacity data transmission between underwater end devices [2]. Space laser communication is gradually becoming the main way to solve the problem of underwater high-capacity data transmission because of its strong anti-interference capability [3], high transmission capacity [4], high rate [5], and fast deployment [6]. However, the reasons affecting the development of UWOC are the scattering and absorption of light by seawater and ocean turbulence, where ocean turbulence subject to changes in salinity, temperature, and seawater density is the main factor affecting beam propagation [7]; turbulence especially causes scintillation effects, resulting in the received light energy showing violent jitter, which will seriously degrade the performance of UWOC systems [8].…”