# Distributed MIMO Measurements for Integrated Communication and Sensing in an Industrial Environment
## 5 Measurement Campaign
### Measured Scenarios  
In this study, the moving agent traversed various paths to simulate conditions relevant to robotics or IoT devices in an industrial setting. Each path was traversed multiple times to ensure a robust statistical foundation for channel evaluations. This repetition also facilitates preliminary assessments of data-driven methodologies and machine-learning techniques based on different scenario realizations. All scenarios originated from a fixed position within the environment. For conciseness, this paper focuses on two primary scenarios, henceforth referred to as _ref_ and _loop_; see Figure 7, which collectively covers critical conditions such as NLoS and LoS links.  
Figure 5: (**a**) A photograph showing a view of the environment. The hall is approximately \(30\,\mathrm{m}\times 11\,\mathrm{m}\) with a ceiling height between \(8\,\mathrm{m}\) to \(10\,\mathrm{m}\) depending on location. (**b**) A photograph showing the placement of four antennas (circled in red). In total, there were twelve distributed antennas; six on each side of the hall. They were situated \(4\,\mathrm{m}\) above the floor, with a separation of \(4\,\mathrm{m}\).  
Figure 6: Example output from FAST-LIO2. The figure depicts the intensity of the points in the scan, and the extra intensity spots on antenna locations with the help of reflective tape, as seen in the circled regions. The cyan colored path shown is an example output of the ground truth position of the user.  
In the _ref_ scenario, the robot navigates centrally through the room for approximately 20 s, executes a 180\({}^{\circ}\) rotation, and returns to its starting point. The whole sequence lasts around 60 s. In the _loop_ scenario, the robot drives two laps around some machinery and work tables. Parts of the trajectory have a much lower ceiling height than the rest of the hall. The _loop_ scenario lasts approximately 80 s. For both scenarios the parameters of the channel sounder are detailed in Table 3.  
We used the remotely controlled robot as an active user in the environment, driving along different paths. The purpose of the measurement was to extract channel statistics for distributed MIMO and to collect channel samples to develop and evaluate positioning algorithms. To achieve this, we collected channel data from routes in the somewhat more open space in the middle of the workshop as well as in the more obstructed parts with blocking from the machinery.  
\begin{table}
\begin{tabular}{l l l l} \hline \hline
**Parameter Description** & **Value** & **Parameter Description** & **Value** \\ \hline Number of antennas, \(H_{\text{a}}\) & 13 & Carrier frequency, \(f_{\text{c}}\) & 3.75 GHz \\ Frequency spacing, \(\Delta f\) & 78.125 kHz & Bandwidth, \(BW\) & 40 MHz \\ Active subcarriers, \(N_{\text{f}}\) & 449 & Number of subcarriers, \(N_{\text{sc}}\) & 512 \\ Signal length, \(\tau_{\text{max}}\) & 12.8 us & Signal repetitions, \(R\) & 4 \\ Snapshot length, \(H_{\text{a}}\cdot R\cdot\tau_{\text{max}}\) & 665.6 us & Repetition rate, \(f_{\text{rep}}\) & 200 Hz (5 ms) \\ Max. resolvable velocity, \(\
u_{\text{max}}\) & 8 m/s & Transmit power, \(P_{\text{TX}}\) & 19 dBm \\ Measurement length, \(T\) & \(T\in\{60,80\}\) & Signal spacing, quite & 4334.4 μs \\ Digital-to-analog back-off, \(A_{\text{DAC}}\) & 0.9 & & \\ \hline \hline \end{tabular}
\end{table}
Table 3: Channel sounding parameters.  
Figure 7: A top-down schematic of the workshop where the measurements were performed. The 12 static antennas are labeled according to the figure. The two paths are depicted where the samples were taken. Machinery or equipment are marked purple, except the machine colored in green which is tall enough to put antenna 8 in NLoS for the majority of the measurements. The part colored in gray is where the ceiling is much lower than the rest of the workshop.