# Integrated Communication and Measurement System with BOC-Assisted OFDM
## 4 Simulation Results and Performance Analysis
### Actual Environment Simulation  
In this paper, a simple UAV networking model is constructed, including a ground station node and four UAV nodes. The structure diagram of the UAV networking model is shown in Figure 17. The UAV nodes B and D cannot communicate with the ground station directly; however, they can communicate with the ground station via UAV nodes A and C indirectly. The actual scenario parameters are as follows: flight height: 1-2 km; flight speed: 80-150 km/h; distance of communication at inter-UAV: 1-5 km; distance of communication between UAV and ground station: 30-50 km; operation frequency: 5 GHz.  
According to the actual scenario parameters, the UAV node A is simulated and analyzed. A comparison of the actual flight trajectory and the measured trajectory is shown in Figure 18. The ranging error is shown in Figure 19. Thus, the accuracy of the range error is controlled within 0.01 m. The flight speed of UAV node A is shown in Figure 20, where the max Doppler frequency offset is 630 Hz. The approach proposed in this paper can achieve a BER of communication below \(10^{-4}\).  
\begin{table}
\begin{tabular}{l c c c} \hline  & **SNR** & **Yes or No** & **BER** \\ \hline \multirow{2}{*}{\(f_{d}=50\,\mathrm{Hz},V=37.7\,\mathrm{km/h}\)} & \(SNR\geq 19\,\mathrm{dB}\) & Yes & \(BER\leq 10^{-4}\) \\ \cline{2-4}  & \(SNR\geq 19\,\mathrm{dB}\) & No & \(10^{-3}<BER<10^{-2}\) \\ \hline \multirow{2}{*}{\(f_{d}=100\,\mathrm{Hz},V=75.4\,\mathrm{km/h}\)} & \(SNR\geq 19\,\mathrm{dB}\) & Yes & \(BER\leq 10^{-3}\) \\ \cline{2-4}  & \(SNR\geq 19\,\mathrm{dB}\) & No & \(10^{-2}<BER<10^{-1}\) \\ \hline \multirow{2}{*}{\(f_{d}=300\,\mathrm{Hz},V=226.2\,\mathrm{km/h}\)} & \(SNR\geq 24\,\mathrm{dB}\) & Yes & \(BER\leq 10^{-4}\) \\ \cline{2-4}  & \(SNR\geq 24\,\mathrm{dB}\) & No & \(BER\approx 0.5\) \\ \hline \multirow{2}{*}{\(f_{d}=500\,\mathrm{Hz},V=377.0\,\mathrm{km/h}\)} & \(SNR\geq 25\,\mathrm{dB}\) & Yes & \(BER\leq 10^{-4}\) \\ \cline{2-4}  & \(SNR\geq 25\,\mathrm{dB}\) & No & \(BER\approx 0.5\) \\ \hline \multirow{2}{*}{\(f_{d}=700\,\mathrm{Hz},V=527.9\,\mathrm{km/h}\)} & \(SNR\geq 23\,\mathrm{dB}\) & Yes & \(BER\leq 10^{-4}\) \\ \cline{2-4}  & \(SNR\geq 23\,\mathrm{dB}\) & No & \(BER\approx 0.5\) \\ \hline \multirow{2}{*}{\(f_{d}=900\,\mathrm{Hz},V=678.7\,\mathrm{km/h}\)} & \(SNR\geq 28\,\mathrm{dB}\) & Yes & \(BER\leq 10^{-4}\) \\ \cline{2-4}  & \(SNR\geq 28\,\mathrm{dB}\) & No & \(BER\approx 0.5\) \\ \hline \end{tabular}
\end{table}
Table 2: Performance comparison of carrier Doppler compensation and channel compensation at different speeds. (\(\alpha\):\(\beta\) = 0.1:0.9 ; “Yes” indicates carrier Doppler compensation, “No” indicates channel compensation).  
Figure 19: Range error under an actual environment.  
Figure 17: The structure diagram of the UAV networking model (The UAV nodes A, B, C, D represent the four UAVs in the UAV networking model, respectively. The UAV nodes A and C can communicate with the ground station and other UAV nodes, the UAV nodes B and D cannot communicate with the ground station).  
Figure 18: Comparison of the actual flight trajectory and the measured trajectory.