## 5 Conclusions  
This paper describes the research on UAV optical communication carried out in recent years, introduces the elemental composition and working principle of visual communication, summarizes and organizes the communication transmission rate and distance as the primary technical parameters, and synthesizes the research status at home and abroad, finding that, since 2013, for lightweight and small-sized uncrewed aerial vehicle (UAV) wireless optical communication systems, their application scenarios have been constantly enriched. At the same time, the requirements for light and small-sized UAV's communication distance and communication rate have also gradually increased. Given the shortcomings of the existing technology, some feasible technical solutions and development proposals are put forward. For example, the adoption of high-speed data transmission protocol and advanced modulation and demodulation technology can improve the transmission rate and stability; the adoption of all-weather technology and stable tracking and alignment technology can increase the transmission distance and anti-jamming ability; and the lightweight and miniaturization technology can reduce the load and delay of UAVs. This has a certain referability. In the future, with the continuous development of UAV technology and the constant expansion of application scenarios, lightweight and small UAV high-speed data transmission technology will face more challenges and machinery. We expect that more advanced \begin{table}
\begin{tabular}{c c c} \hline \hline
**Key Technologies** & **Methodologies** & **Verdict** \\ \hline \multirow{6}{*}{Modulation and demodulation techniques} & Approach to real-time processing using optical transport networks & Successful transmission of 100 Gbit/s and 125 Gbit/s PDM-QPSK signals \\ \cline{2-3}  & Uses 1-channel dense wavelength division multiplexing & Bit error rate of \(10^{-12}\) \\ \cline{2-3}  & Integration of RoF and RoF-FSO & A visual range of up to 100 meters with error-free transmission. \\ \hline \multirow{6}{*}{Capture alignment tracking technology} & Improved beaconless capture algorithm & The use of such a sub-area scanning approach results in a wider capture uncertainty domain. \\ \cline{2-3}  & Beaconless helical capture scanning technology & Improved follow-through stability \\ \hline \multirow{6}{*}{All-weather technology} & Analyzing the Shannon limit communication rate for optical communications in atmospheric channels & Need for real-time feedback on channel characteristics \\ \cline{2-3}  & Integrated design of independent beacon light & The mass of the terminal is 7.5 kg \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Summary of key technology studies. high-speed data transmission technologies will emerge to provide more stable, efficient, and reliable data transmission support for light and small UAV applications. The next step in advancing high-speed data transmission technology for UAVs should focus on the integration and validation of the technology. This includes integrating new optical signal transmission technologies, smaller optical communication devices, optimized UAV positioning and tracking algorithms, and advanced data processing and analysis techniques to form a complete and efficient data transmission system. Subsequently, it should be tested in an actual UAV environment to ensure the effectiveness and reliability of the technology. It is also necessary to consider how these techniques can be better applied to actual UAV communication missions. Conceptualization, D.J. and S.B. ; methodology, D.J. ; software, D.J. and X.Y. ; investigation, D.J. and G.H. ; writing\(-\)original draft preparation, D.J. ; writing\(-\)review and editing, D.J., S.B., X.Y., X.L., G.H. and J.H. ; project administration, S.B. All authors have read and agreed to the published version of the manuscript.