Performance evaluation of DP-QPSK modulation for underwater optical wireless communication using a green light propagation

In comparison to radio frequency and acoustic communication, underwater optical wireless communication (UOWC) has garnered greater attention recently due to its higher data rate and low latency. In this paper, we proposed underwater optical communication by using free-space optical communication (FSO) system to propagate the green light waves through the water. The application of three different modulation schemes, including quadrature phase shift keying(QPSK), dual-polarization quadrature phase shift keying (DP-QPSK), and 4-quadrature amplitude modulation (4-QAM) are designed not only to focus on the analysis of problems like attenuation, absorption, scattering, and turbulence but also investigates spectral efficiency. The Performance and physical aspects of the above modulation techniques with UOWC are studied and a comparison of multiple criteria, including the maximum quality factor, the minimum bit error rate (BER), and the eye diagram.