Fig. 1. The block diagram of the UWOC system with OQPSK modulation scheme

Fig. 2. Demodulation schematic of OQPSK

Fig. 3. Schematic of beam expansion

Fig. 4. Flowchart of acceptance-rejection sampling algorithm

Fig. 5. EGG distribution probability density function diagram and random noise histogram

Fig. 6. Comparison of BER performance of OQPSK modulation system in composite channels with different turbulence intensity

Fig. 7. Comparison of BER performance of different modulations in composite channels

Fig. 8. OQPSK-UWOC system transmission model

Fig. 9. OQPSK modulation signal through different channel

Fig. 10. Comparison of OQPSK signal waveform of different turbulence coherence time

Fig. 11. Comparison of BER performance for different coherent time in composite channels

Fig. 12. Comparison of BER performance for different transmission distances and turbulence intensities in composite channels

Fig. 13. Comparison of BER performance for different transmission distances in composite channels

Fig. 14. Comparison of BER performance for different noise power in composite channels

Fig. 15. Comparison of BER performance for different water quality in composite channels