# Path Loss Measurements and Model Analysis in an Indoor Corridor Environment at 28 GHz and 38 GHz
## 3 Path Loss Measurements and Models
### Measurement Setup  
The setups used for the measurement, the measurement scenario, and the channel sounder are shown in Figure 2. The measurements were carried out at the Howard College Campus of the University of KwaZulu-Natal on the 5 th floor of the Department of Electrical, Electronic, and Computer Engineering. The measurements were conducted at frequencies of 28 and 38 GHz with a transmitting antenna height of 1.6 m and receiving antenna height of 2.3 m. There was a total of 13 measured points for the both LOS and NLOS scenarios. Although a reference distance of 1 m was observed, subsequent measurements were done from 2 m points with increments of 2 m each until reaching 24 m. The measurements for Tx and Rx combinations included two antenna polarization combinations, i.e., V-V and V-H. For the LOS, the bore sight alignments of the two antennas were used. Whereas, in the NLOS scenario, the received power was determined when the transmitting antenna was rotated to make sure there was an obstruction resulting in no clear optical path between the Tx and Rx antennas. At this point, there was no aligning bore sight between the two antennas. The complete description of the channel sounder, as well as the measurement setup, are provided. On the transmitting end, the Rhode and Schwarz SMB 100A radio signal generator was used to generate continuous wave (CW) signals, which then radiated across a wireless medium. This signal generator has a frequency range of 100 KHz to 40 GHz. A Rhode and Schwarz FSIQ 40 signal analyzer was used at the receiver end to receive the continuous wave signal from the SMB 100A signal generator. The frequency range of this FSIQ 40 signal analyzer is 20 to 40 GHz with a maximum bandwidth of 120 MHz. Two identical LB-180400-KF broadband horn antennas with frequency ranges of 18 to 40 GHzwere used in this setup for transmitting and receiving radio signals. They had a nominal gain of 15 dBi, a low VSWR of 1.5:1, and a uniform gain across the frequency ranges, resulting in efficient performances and directionality. The antennas were also linearly polarized and could handle 10 W continuously and 20 W peak output. In the elevation plane, the half-power beam width (HPBW) had a minimum of 21 degrees and a maximum of 42 degrees, whereas, in the H-plane, it was a minimum of 17 degrees and a maximum of 45 degrees. The measurements were conducted at the height of 1.6 m for the transmitting antenna and 2.3 m for the receiving antenna above the floor for both LOS and NLOS situations. Figures 3-6 present the transmitter setup, receiver setup, and indoor corridor environment. Table 1 lists the channel sounder's parameter settings. Figure 4: The transmitter setup. Figure 3: The indoor corridor environment. Figure 2: The architecture of the channel sounder. The measuring campaigns took place on the 5 th floor of the Electrical, Electronic, and Computer Engineering Department at the University of KwaZulu-Natal in Durban, South Africa. The length, height, and width of the indoor corridor are 30, 2.63, and 1.4 m, respectively. The corridor is made up of dry concrete brick walls, a square tiled floor, an elevator, and wooden office doors. The floor plan is shown in Figure 7. The indoor corridor was used for both the LOS and NLOS scenarios of the campaign. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameters** & **Configuration** & **Unit** \\ \hline Center frequency & 28, 38 & GHz \\ Bandwidth & 100 & MHz \\ Transmission signal & Continuous wave & \\ Tx and Rx Antennas & Broadband horn antenna & \\ Tx Antenna power & 10 & dBm \\ Tx Antenna height & 1.6 & m \\ Rx Antenna height & 2.3 & m \\ Tx and Rx antenna gain at 28 GHz & 15 & dBi \\ Tx and Rx antenna gain at 38 GHz & 17 & dBi \\ Tx and Rx antenna polarization & Vertical/horizontal & \\ Antenna size L \(\times\) W \(\times\) H & 71 \(\times\) 32 \(\times\) 28.6 & mm \\ Antenna weight & 0.08 & Kg \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Parameter specifications of the channel sounder. Figure 5: The receiver setup.