## 4 Simulation Results and Analysis
### Non-Real-Time Applications  
Figure 2 depicts the EEs of the satellite user versus the number of iterations in Algorithm 1 with different \(P_{av}/P_{m}\) and \(I_{th}\). It can be seen that Algorithm 1 is convergent for all parameters considered, which proves the effectiveness of the proposed iterative algorithm. Moreover, we can find that all the simulation results would converge within 3 iterations. That is to say, the proposed Algorithm 1 can efficiently find the optimal EE for the satellite user.  
Figure 3 shows the optimal EEs of the satellite user versus \(I_{th}\) with different \(P_{av}\) and \(P_{m}\) for the non-real-time applications. It can be found that the EEs of satellite user improves with the increase of \(I_{th}\). This is because the larger \(I_{th}\) is, the more transmit power satellite user can obtain, which correspondingly lead to a higher EE. However, when \(I_{th}\) is sufficiently large, the EE of the satellite user would get saturated since the transmit power constraints become the dominant constraints in this case. In addition, our findings suggest that the EEs of the satellite user with ATP constraint are higher than those with the PTP constraint, this is due to the fact that in PTP cases, the satellite user utilizes the instantaneous CSI, which results in a stricter power constraint than those of ATP cases with statistical CSI. Meanwhile, the EEs of the satellite user also improve with the increase of transmit power constraints.  
Figure 4 shows the optimal EEs of the satellite user in different terrestrial interference links. All the EEs of the satellite user with ATP constraint are higher than those with the PTP constraint under the same channel conditions, which is consistent with the findings in Figure 3. With the same transmit power constraint, the EE of the satellite user decreases with the increase of \(\Omega_{I}\), which can  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameters** & **Values** \\ \hline signal frequency (\(f\)) & 2 GHz \\ \(G_{t,\max}\) & 42.1 dB \\ \(G_{r,\max}\) & 52.1 dB \\ \(G_{BS}\) & 0 dB \\ \(\theta\) & 20\({}^{\circ}\) \\ \(\psi\) & 50\({}^{\circ}\) \\ \(N_{s}\) & 0.01 W \\ \(\xi\) & 0.2 \\ \(P_{c}\) & 0.05 W \\ \(R_{th}\) & 2 bit/s/Hz \\ satellite link distance (\(d_{s}\)) & 35,786 km \\ interference link distance (\(d_{p}\)) & 10 km \\ \(t_{1}\), \(t_{2}\) & 0.1 \\ \(\xi_{0}\), \(\xi_{1}\), \(\xi_{2}\) & \(5\times 10^{-3}\) \\ \(m_{S}\) & 10 \\ \(\Omega_{S}\) & 0.835 \\ \(b_{S}\) & 0.126 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Simulation Parameters.  
be explained by the fact that the terrestrial interference link would become stronger with larger \(\Omega_{I}\). However, the saturated EE values under the same transmit power constraint are identical when \(I_{th}\) is large enough, since the transmit power constraints dominate in this case and the limits are the same as mentioned above.  
Figure 4: The EEs of the satellite user versus \(I_{th}\) with different transmit constraints and interference link conditions with \(P_{av}\ =\ P_{m}\ =\ 0.05\) W and \(m_{I}\ =\ 1\).  
Figure 3: The EEs of the satellite user versus \(I_{th}\) with different \(P_{av}\) and \(P_{m}\) with \(m_{I}\ =\ 1\) and \(\Omega_{I}\ =\ 1\).  
Figure 2: The EEs of the satellite user versus number of the iterations in Algorithm 1 with \(m_{I}\ =\ 1\) and \(\Omega_{I}\ =\ 1\).