## 5 Experiment, Results and Discussion
### Experiment Set Up and Data Collection
#### 5.1.2 Data for Training Network Model  
We use the diagnostic data as the input data for our classifier. So both the MLP model and the CNN model we established have eight input neurons. As shown in Table 1, eight symbols of the transmitting data are involved in our diagnostic data.  
According to the DW1000 Software API Guide and the DW1000 user manual, in the above diagnostic data, \(stNoise\) reported in the register file may be used to give a measure of the noise associated with this and the received frame's timestamp measurement. firstPathAmp1, firstPathAmp2, firstPathAmp3 are 16-bit unsigned values that are part of reporting the magnitude of the leading edge signal seen in the accumulator data memory during the LDE algorithm's analysis. In addition to stdNoise, other data types will be used to calculate the first path power level and the receive power level. High noise may  
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Serial Number** & **Symbols** & **Meaning** \\ \hline \multirow{3}{*}{1} & firstPathAmp1 & the magnitude of the accumulator tap at the index 3 beyond the integer portion of the rising edge FP\_INDEX reported in Register \\ \cline{2-3}  & firstPathAmp2 & the magnitude of the accumulator tap at the index 2 beyond the integer portion of the rising edge FP\_INDEX reported in Register \\ \hline \multirow{3}{*}{3} & firstPathAmp3 & the magnitude of the accumulator tap at the index 1 beyond the integer portion of the rising edge FP\_INDEX reported in Register \\ \cline{2-3}  & stdNoise & the standard deviation of the noise level seen during the LDE algorithm’s analysis of the accumulator data. \\ \hline \multirow{3}{*}{5} & maxGrowthCIR & a growth factor for the accumulator which is related to the receive signal power. \\ \cline{2-3}  & firstPathdex & the position within the accumulator that the LDE algorithm has determined to be the first path. \\ \cline{2-3}  & rxPreamCount & the number of symbols of preamble accumulated. \\ \hline \multirow{3}{*}{8} & \multirow{3}{*}{C} & the Channel Impulse Response Power value reported in the CIR\_PWR field of Register file \\ \cline{2-3}  & & \\ \hline \hline \end{tabular}
\end{table}
Table 1: Symbols of the frame transmit data we used to read from the registers.  
Figure 12: The UWB node. The device we use is produced by China Jiuling electronics manufacturer, whose Chinese name is printed on the surface of the device.  
mean that the real first path is irretrievably buried in the noise. Comparing the noise with the First Path Amplitude can give additional indication as to the quality of the first path measurement. So those features can be used in assessing the quality of the received signal. In order to obtain the LOS sample data and the NLOS sample data with these eight characteristics, we designed an experimental system to collect the LOS sample data and the NLOS sample data, respectively. Figure 13 shows a top view of our experimental scenario.  
We marked the location of the tag, before the data is collected. For the collection of NLOS data, we moved 1 m to the east of the map each time, and collected a group of several NLOS samples at each location. A total of 11 moves can collect 12 sets of data. For the collection of LOS data, we move 2 m to the south of the map each time, and collect a set of LOS sample data of a certain number at each position, moving a total of 53 times, that is, 54 sets of data can be collected. Each sample data includes the ranging values and eight features described in the previous paragraph. Table 2 shows the number of sample data collected by out experiments.