Fig. 1. Schematic diagram of the transceiver based on random modulation

Fig. 2. (a) Correlation coefficient analysis of two consecutive observations of \begin{document}${\tilde \phi _{{{\rm{A}}}}}\left( t \right)$\end{document} in the case of signal modulation \begin{document}$\sigma _{x,{{{\rm{A}}}}}^2 > 0,\sigma _{x,{{{\rm{B}}}}}^2 \equiv 0$\end{document}；(b) Correlation coefficient analysis of two consecutive observations of \begin{document}${\phi _{{{\rm{A}}}}}\left( t \right)$\end{document} in the case of double modulation\begin{document}$\sigma _{x,{{{\rm{A}}}}}^2 \equiv \sigma _{x,{{{\rm{B}}}}}^2 > 0$\end{document}

Fig. 3. Schematic diagram of optical channel sample measurement system based on random modulation

Fig. 4. (a) Real-time measurement data plot in the case of no modulation; (b) Real-time measurement data plot in the case of single modulation; (c) Real-time measurement data plot in the case of double modulation; (d), (e), and (f) are the 0 -0.119 × 10⁻³ s measurement data plots in different modulation cases, respectively

Fig. 5. Comparative analysis of autocorrelation for different modulations

Fig. 6. Comparative analysis diagram of atmospheric optical channel transmission coefficients with different coherence times

Fig. 7. (a) Comparative analysis diagram of pseudo random code with different generation rates; （b）Autocorrelation analysis diagram of adjacent measurement samples

Fig. 8. Plot of comparative analysis of autocorrelation at different distances

Fig. 9. (a) Comparative analysis of autocorrelation with a SNR of 12.01 dB; (b) Comparative analysis of autocorrelation with a SNR of −15.89 dB