Underwater optical wireless communication system based on dual polarization states with optical code division multiple access: performance evaluation

In this paper, dual polarization (DP) states and optical code division multiple access (OCDMA) are utilized in an underwater optical wireless communication system (UOWCS). The diagonal permutation shift (DPS) code sequences are assigned to the six OCDMA channels that are utilized in the proposed model. These six channels are divided into two groups, each of which transmits its data on DP states. Attenuations of five water types are considered which have different inherent optical characteristics. Bit Error Rate (BER), Quality factor (Q-factor), data rate, underwater (UW) range, and eye patterns are metrics considered for evaluating the proposed UOWCS performance. The outcomes indicate that when the system is used in pure sea (PS) and clear ocean (CL), it shows longer UW ranges of 11 m and 9 m, respectively, with a BER less than 10 –6 , and a Q-factor ∼ 5. In contrast, this range is decreased to 2.75 m when harbor II (HA II) water is used. These ranges are obtained when each channel carries 10 Gbps and as six channels are used, accordingly, the overall achieved capacity is 6 × 10 Gbps = 60 Gbps.