Fig. 1. Beam spread diagram

Fig. 2. Values of α and β in different turbulent regions 不同湍流区域的 和 值

Fig. 3. (a) =0.5 Gamma-Gamma probability density function and Gaussian distribution function; (b) Gamma-Gamma random noise distribution of different logarithmic intensity variances (a) =0.5 Gamma-Gamma概率密度函数和高斯分布函数；(b) 不同对数强度方差的Gamma-Gamma分布随机噪声直方图

Fig. 4. Block diagram of GMSK signal modulation

Fig. 5. Block diagram of GMSK demodulation

Fig. 6. Underwater wireless optical communication system

Fig. 7. (a) Waveform of GMSK modulated optical signal through channel; (b) Comparison of signal waveform before and after SNR=10 dB demodulation

Fig. 8. (a) Comparison of BER performance of OOK modulation, PPM modulation and GMSK modulation in attenuation channels; (b) Comparison of BER performance of OOK modulation, PPM modulation and GMSK modulation in composite channels

Fig. 9. Comparison of system BER performance of GMSK modulation in composite channels with different turbulence logarithmic intensities variance

Fig. 10. Relationship between different transmission distances and SNR in composite channel

Fig. 11. Relationship between turbulence logarithmic intensity variance and limit BER in composite channel