## 3 Results
### Ground--GEO Satellite Link  
We start by detailing the properties and characteristics used in the experiment. To begin with, the forward link is characterized by the transmission of the signal from the ground to the satellite. In Table 1, we highlighted the coordinates of the ground station and the satellite. To obtain the transmission parameters, such as the EIRP detailed in the previous section, we consider that the characteristics of the transmitter at the ground station used to emit the signal to the satellite are those detailed in Table 2. These parameters have values similar to the actual values of these types of communication systems. Along with the emission of the signal, the link must also be characterized so that considering all the elements defined in Section 2 can be determined. For this, in Table 3 we detail the properties of the link. We chose the working frequency of the communication link in the Ku band because many existing systems work in this band. In order to evaluate the performance of the implemented forward link, at the reception we consider the parameters of the satellite receiver detailed in Table 4.  
Thus, based on these considerations, we can obtain the desired values for the notions of interest described in Section 2. One of the priorities of the link design is the determination of the loss value, which affects the signal strength. As we discu \begin{table}
\begin{tabular}{c c c} \hline
**Parameter** & **Ground Station** & **Satellite** \\ \hline Latitude [deg] & 40.71 & 39.2 \\ Longitude [deg] & \(-\)74 & \(-\)51.2 \\ Altitude [km] & 0.035 & 35,786 \\ \hline \end{tabular}
\end{table} 
Table 1: Ground station and satellite proprieties. \begin{table}
\begin{tabular}{c c} \hline
**Parameter** & **Value** \\ \hline Tx feeder loss [dB] & 1 \\ Other Tx losses [dB] & 2 \\ Tx HPA power [dBW] & 23 \\ Tx HPA OBO [dB] & 6 \\ Tx antenna gain [dBi] & 35 \\ \hline \end{tabular}
\end{table} 
Table 2: Ground station transmitter proprieties. \begin{table}
\begin{tabular}{c c} \hline
**Parameter** & **Value** \\ \hline Frequency [GHz] & 14 \\ Bandwidth [MHz] & 6 \\ Bit rate [Mbps] & 10 \\ Required Eb/No [dB] & 5 \\ Availability [\%] & 99.9 \\ Polarization mismatch [deg] & 20 \\ Implementation loss [dB] & 1 \\ Antenna mispointing loss [dB] & 1 \\ Radome loss [dB] & 1 \\ \hline \end{tabular}
\end{table} 
Table 3: Link proprieties. two losses to analyze: FSPL and the total atmospheric losses. Their evolution is shown in Figure 2. At the reception, the interest is given by the RIP, and in order to evaluate the margin, we also need the Eb/No ratio. Their evolution is shown in Figure 3.  
Thus, in Table 5 we have the desired results for the forward link budget. These correspond to a favorable situation in which the quality of the signal is not drastically affected by external factors. What we propose next is to see how the type of modulation used for the transmission of information affects the satellite link and implicitly the qualitative reception of the information. We do this with the help of the margin because we want to see what type of modulation allows an extra level of power. In the analysis carried out, we considered three families of modulations used on a large scale in the field of satellite communications: Phase-shift keying (PSK), Differential Phase Shift Keying (DPSK), and Quadrature \begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Value** \\ \hline Interference loss [dB] & 2 \\ Rx G/T [dB/K] & 22 \\ Rx feeder loss [dB] & 1 \\ Other Rx losses [dB] & 1 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Satellite receiver proprieties. Figure 3: The variation in the main reception parameters of the 14 GHz link depending on the distance or frequency: (**a**) Received Eb/No; (**b**) Received isotropic power. Figure 2: The variation in the main losses of the 14 GHz link depending on the distance or frequency: (**a**) Free space path loss; (**b**) Total atmospheric losses. Amplitude Modulation (QAM).