## 3 TVWS-DTV Coexistence: Field Measurements
### Field Tests Considering Long Distances
#### 3.2.4 Results from the First Stage of Field Tests
\begin{table}
\begin{tabular}{c l c c c c c c} \hline \hline  & \multicolumn{2}{c}{\(P_{\text{TX}}\)**TVWS (CH28) [Wp]**} & **1** & **2** & **4** & **1** & **2** & **4** \\ \cline{2-9}
**DTV** & \multicolumn{2}{c}{**Filter\({}_{\text{RX}}\) (CH28)**} & \multicolumn{4}{c}{**Yes**} & \multicolumn{4}{c}{**Yes**} \\ \cline{2-9}
**Channel** & \multicolumn{2}{c}{**LNA\({}_{\text{RX}}\)**} & \multicolumn{4}{c}{**Off**} & \multicolumn{4}{c}{**On**} \\ \hline  & \multicolumn{2}{c}{\(P_{\text{RX}}\) DTV (CH27) [dBm] \(-77.5\) & \(-77.5\) & \(-77.4\) & \(-77.5\) & \(-77.4\) & \(-77.5\) \\ \cline{2-9}
**27** & \multicolumn{2}{c}{\(P_{\text{RX}}\) TVWS (CH28) [dBm] \(-80.2\)} & \(-76.5\) & \(-73.7\) & \(-57.1\) & \(-53.2\) & \(-50.5\) \\ \cline{2-9}
**27** & \multicolumn{2}{c}{\(\text{PR}_{(n+1)}\) [dB]} & \(2.7\) & \(-1.0\) & \(-3.7\) & \(-20.4\) & \(-24.2\) & \(-27.0\) \\ \cline{2-9}  & \multicolumn{2}{c}{\(\text{ACPR}_{\text{UPPER}}\) [dB]} & \(-2.7\) & \(1.0\) & \(3.7\) & \(20.4\) & \(24.2\) & \(27.0\) \\ \cline{2-9} Interf. & \multicolumn{2}{c}{\(\text{ACPR}_{\text{LOWER}}\) [dB]} & \(-16.0\) & \(-16.0\) & \(-16.0\) & \(-16.0\) & \(-15.9\) & \(-15.9\) \\ \cline{2-9} \(n+1\) & \multicolumn{2}{c}{\(P_{\text{RX}}\) INT. (CH30) [dBm]} & - & - & - & \(-84.1\) & \(-84.1\) & \(-84.1\) \\ \cline{2-9}  & \multicolumn{2}{c}{DTV STB Status 1} & OK & OK & OK & OK & OK & OK \\ \cline{2-9}  & \multicolumn{2}{c}{DTV STB Status 2} & OK & OK & OK & OK & OK & OK \\ \hline  & \multicolumn{2}{c}{\(P_{\text{RX}}\) DTV (CH29) [dBm] \(-77.1\)} & \(-77.0\) & \(-77.0\) & \(-77.0\) & \(-77.0\) & \(-77.0\) \\ \cline{2-9}  & \multicolumn{2}{c}{\(P_{\text{RX}}\) TVWS (CH28) [dBm] \(-78.9\)} & \(-75.1\) & \(-72.3\) & \(-55.2\) & \(-51.5\) & \(-48.7\) \\ \cline{2-9}
**29** & \multicolumn{2}{c}{\(\text{PR}_{(n-1)}\) [dB]} & \(1.8\) & \(-1.9\) & \(-4.7\) & \(-21.8\) & \(-25.5\) & \(-28.3\) \\ \cline{2-9}  & \multicolumn{2}{c}{\(\text{ACPR}_{\text{UPPER}}\) [dB]} & \(-16.4\) & \(-16.2\) & \(-16.2\) & \(-8.9\) & \(-8.9\) & \(-8.9\) \\ \cline{2-9} Interf. & \multicolumn{2}{c}{\(\text{ACPR}_{\text{LOWER}}\) [dB]} & \(-1.8\) & \(1.9\) & \(4.7\) & \(21.8\) & \(25.5\) & \(28.3\) \\ \cline{2-9} \(n-1\) & \multicolumn{2}{c}{\(P_{\text{RX}}\) INT. (CH30) [dBm]} & - & - & - & \(-85.9\) & \(-85.9\) & \(-85.9\) \\ \cline{2-9}  & \multicolumn{2}{c}{DTV STB Status 1} & OK & OK & OK & OK & OK & OK \\ \cline{2-9}  & \multicolumn{2}{c}{DTV STB Status 2} & OK & OK & OK & OK & OK & OK \\ \cline{2-9}  & \multicolumn{2}{c}{DTV STB Status 3} & OK & OK & OK & OK & OK & OK \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Coexistence tests results in MS_Loteamento with LNA turned on and off. Table 9. It is noteworthy that for a \(P_{\text{TX}}\) TVWS of 6.3 Wp, a PR of \(-30.2\) dB was obtained, for which all three STBs had \"OK\" DTV STB Status. When \(P_{\text{TX}}\) TVWS was increased to 8 Wp, a PR of \(-31.1\) dB was calculated, and STB 1 presented an \"Intermittent\" DTV STB Status. Finally, with a \(P_{\text{TX}}\) TVWS of 10 Wp, a PR of \(-31.9\) dB was obtained, and STBs 1 and 2 had \"Not OK\" and \"Intermittent\" DTV STB Status, respectively. The input spectrum of the DTV STBs in the threshold condition for all three STBs to work simultaneously is shown in Figure 12(a). The DTV signal is in the center of the spectrum, and the TVWS signal is on the left, while the signal on the right is the vestige of the interfering DTV signal present on channel 30 after filtering. Additionally, at the MS_Loteamento location, tests were conducted considering the simultaneous interference on channels \(n+1\) and \(n-1\). In these tests, the DTV signal under analysis was configured on channel 29, and the \(P_{\text{TX}}\) TVWS was set to 4 Wp, considering the \(\text{LNA}_{\text{RX}}\) on and without using Filter\({}_{\text{RX}}\). This allowed usi  
Figure 13: (a) Input spectrum of the DTV STB for 6.3 Wp and with LNA in reception. (b) Input spectrum of the DTV STB for 4 Wp, with LNA in reception, removing the filter, and with a 4 dB attenuation in reception.