## 3 Results
### Corridor  
Wideband results obtained in the corridor, in both LOS and OLOS, were processed in a similar way. Tables 3 and 4 provide RMS delay spread values and Tables 5 and 6 coherence bandwidth values, for LOS and OLOS conditions.  
Observing Tables 3 and 4, one can notice a clear difference between 40 GHz and 60 GHz. Both in LOS and OLOS, the 60 GHz signals demonstrate a lower delay spread. Indeed, the lower the frequency the more multipath is observed in the measurement campaign. Obviously, the multipath scheme is the same in both environments. However, the attenuation at 60 GHz is stronger than at 40 GHz as many multipath components at 60 GHz arrive at the receiver with a level below its sensitivity, and hence do not contribute to the received signal. Less multipath components result in a lower RMS delay spread.  
The difference in RMS delay spread between LOS and OLOS is clear at 60 GHz, with lower values in LOS and with a stronger dominant direct path than in OLOS. The difference is not so clear at 40 GHz.  
In general, the coherence bandwidth in these corridor scenarios is higher in the first part of the rail. After a certain distance, it drops to nearly half its value. The drop appears around 130 cm for 60 GHz and 150 cm for 40 GHz. There are two explanations for this behavior. The first one is that the antenna quits the main lobe, resulting in a weaker value in the PDP. The second one is that the multipath components are reduced, due to the environment geometry.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Band** & **Channel 21** & **Channel 31** & **Channel 41** \\ \hline
40 GHz & 6.9 & 8.4 & 8.7 \\
60 GHz & 4.1 & 5.1 & 3.7 \\ \hline \end{tabular}
\end{table}
Table 4: RMS delay stays below this value (ns) 99% of the time, in the corridor, OLOS.  
Figure 14: Theoretical Fleury limit and measured results, for different correlation levels \(\alpha\) = 0.5, 0.7, or 0.9, at the auditorium in the 60 GHz band, received by antenna “3”.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Band** & **Channel 21** & **Channel 31** & **Channel 41** \\ \hline
40 GHz & 7.4 & 8.4 & 5.4 \\
60 GHz & 0.1 & 0.1 & 0.1 \\ \hline \end{tabular}
\end{table}
Table 3: RMS delay stays below this value (ns) 99% of the time, in the corridor, LOS.  
In the LOS scenario, the coherence bandwidth is higher at 40 GHz than at 60 GHz, as can be seen in Table 5. As previously stated, this is expected due to the higher amount of multipath. In OLOS (Table 6) the 60 GHz seems to be higher, but this is due to the absence of received signal at some places along the path.  
Regarding the theoretical limits for the coherence bandwidth, Figure 15 shows the Fleury's limit for the case of the measurements in the 40 GHz band at the corridor.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Band**} & **Correlation Level** & **Received by Antenna “2”** & **Received by Antenna “3”** & **Received by Antenna “4”** \\ \hline \multirow{2}{*}{40 GHz} & 0.5 & 96 & 84 & 78 \\  & 0.7 & 72 & 66 & 60 \\  & 0.9 & 4 & 4 & 4 \\ \hline \multirow{2}{*}{60 GHz} & 0.5 & 126 & 108 & 120 \\  & 0.7 & 96 & 84 & 90 \\ \cline{1-1}  & 0.9 & 54 & 48 & 54 \\ \hline \hline \end{tabular}
\end{table}
Table 6: The 99 th percentile of coherence bandwidth (MHz), in the corridor, OLOS.  
Figure 15: _Cont._  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Band**} & **Correlation Level** & **Received by Antenna “2”** & **Received by Antenna “3”** & **Received by Antenna “4”** \\ \hline \multirow{2}{*}{40 GHz} & 0.5 & 282 & 264 & 306 \\  & 0.7 & 144 & 156 & 191 \\  & 0.9 & 12 & 12 & 12 \\ \hline \multirow{2}{*}{60 GHz} & 0.5 & 209 & 179 & 227 \\  & 0.7 & 48 & 18 & 12 \\  & 0.9 & 12 & 6 & 6 \\ \hline \hline \end{tabular}
\end{table}
Table 5: The 99 th percentile of coherence bandwidth (MHz), in the corridor, LOS.