## 7 Conclusions
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**System Parameters** & **Symbol** & **System Parameters** & **Symbol** & **System Parameters** & **Symbol** & **System Parameters** & **Symbol** \\ \hline the primary signal & \multirow{2}{*}{\(P_{M}\)} & the secondary signal & \multirow{2}{*}{\(S_{n_{f_{2}}}\)} & the transmitted & \multirow{2}{*}{**S**} & Light wavelength & \multirow{2}{*}{\(\lambda\)} \\ constellations & & constellations & & signal & & & \\ \hline EFOGSM signal & \(\mathbf{x_{k}}\) & Coding ratio & R & modulation order & M & Link distance & d \\ \hline the complement of & \multirow{2}{*}{\(\overline{\mathbf{x}}_{k}\)} & the data transmission & \multirow{2}{*}{Rp} & the average signal to & \multirow{2}{*}{\(\rho\)} & \multirow{2}{*}{Optical beam width} & \multirow{2}{*}{\(w_{z}\)} \\ a signal & & rate & & noise ratio & & & \\ \hline The number of & \multirow{2}{*}{\(N_{u}\)} & the number of lasers & \multirow{2}{*}{\(N_{t}\)} & the detection & \multirow{2}{*}{\(\omega\)} & the attenuation & \multirow{2}{*}{\(\sigma\)} \\ activated lasers & & & & & & photodetector & \\ \hline \multirow{4}{*}{the transmit power} & \multirow{4}{*}{\(R_{t}\)} & The classical & \multirow{4}{*}{\(\xi\)} & the additive white & \multirow{2}{*}{**n**} & \multirow{2}{*}{Path loss} & \multirow{2}{*}{\(h_{t}\)} \\ the transmit power & & & component’s average & & Gaussian noise & & \\ \hline \multirow{4}{*}{the modified Bessel function of order v} & \multirow{4}{*}{\(K_{\varepsilon}(\cdot)\)} & the standard & \multirow{4}{*}{\(\delta_{s}\)} & \multirow{4}{*}{Pointing error} & \multirow{4}{*}{\(h_{p}\)} & a positive parameter & \multirow{4}{*}{\(\alpha\)} \\ the modified Bessel function of order v & & deviation of the & & & related to effective & & \\ \cline{1-1} \cline{5-5}  & & pointing error & displacement at & & large-scale cells in the & \multirow{2}{*}{\(\alpha\)} \\ the receiver & & & & & scattering process & \\ \hline the channel gain & \multirow{2}{*}{\(\mathbf{H}\)} & the received optical & \multirow{2}{*}{\(A_{0}\)} & \multirow{2}{*}{slot time} & \multirow{2}{*}{T} & a natural number & \multirow{2}{*}{\(\beta\)} \\ the channel gain & & power & & & representing the & & number of \\ \cline{1-1} \cline{5-5}  & & & power & & & fading parameters & \\ \hline the Hamming distance & \multirow{2}{*}{\(d_{H}(\mathbf{x}_{i},\mathbf{x}_{j})\)} & Deterministic & \multirow{2}{*}{\(\Phi_{A}\)} & Component of & \multirow{2}{*}{\(\Phi_{B}\)} & the equivalent & \multirow{2}{*}{\(w_{zeq}\)} \\ the average optical & & & component & & scattering & & beam width \\ \hline the average optical & \multirow{2}{*}{\(\Omega\)} & The average power & \multirow{2}{*}{\(2h_{0}\)} & the radius in the & \multirow{2}{*}{\(r\)} & represents the & \multirow{2}{*}{\(\eta\)} \\ power of the & & of the total & & transverse plane of & & amount of scattered \\ LOS term & & scatter components & & the incident wave & & power coupled & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Parameter variable. **Author Contributions:** Methodology, R.Z. ; software, R.Z. ; validation, R.Z. ; formal analysis, Y.W. ; writing--original draft preparation, R.Z. ; writing--review and editing, R.Z. and Y.W. ; supervision, Y.W. All authors have read and agreed to the published version of the manuscript. **Funding:** This research was funded by the Open Project Program of Building Energy-Saving Engineering Technology Center in Anhui Province under Grant (No. AHJZIN-2021-02); the National Natural Science Foundation of China (No. 51704267). **Data Availability Statement:** Not applicable. **Conflicts of Interest:** The authors declare no conflict of interest.