## 4 System Analysis and Experiment  
### System Setup and Dual-Receiving Method  
When constructing the acoustic signal data set, it is essential to consider various shielding ways that actually happen in the scenarios. At the same time, no more than one random transmission path is supposed to be blocked in a single localization loop. Meanwhile, only when two pieces of chirp acoustic signals received by each acoustic anchor are both blocked, they are regarded as NLOS acoustic signals at that moment. The green dot lines in Figure 6 below besiege the indoor localization area. Meanwhile, it is supposed to consider the dynamic NLOS situations. So, we finish the patrol route for the system, which is shown in Figure 6 below by red arrow. All of the pedestrians or runners moving with the routes take shape in our man-made flexible NLOS situations. With the necessary functions and strategies in [20, 21, 22], the overall framework of the indoor localization system is as follows. \begin{table}
\begin{tabular}{c c c} \hline
**AFSA-SVM Optimization Method** & **Average Running Time of This Method(s)** & **Accuracy** \\ \hline AFSA optimization method in [22] & 121.54 & 75.00\% \\ AFSA optimization method in [39] & 87.43 & 70.52\% \\ AFSA optimization method in [40] & 101.92 & 85.89\% \\ AFSA optimization method in [41] & 89.01 & 82.13\% \\ Our AFSA optimization method (CTGSA time is not added) & 65.91 & 82.19\% \\ \hline \end{tabular}
\end{table} 
Table 1: Comparison of some AFSA-SVM optimization method effects. Although the COVID issue and some other negative factors brought us some troubles, we still gathered nine people as our NLOS man-made dynamic and flexible scenario production volunteers. Eight of them were male and one was female. They all had enough comprehension ability to complete the instructions as required. They were not influenced by diseases that could affect normal human actions during the experiment. At the same time, we also took into account the negative impact of the volunteers' physical energy decline as the experiment proceeded, so that each volunteer could not experiment for more than an hour. Specifically, volunteers followed the designed route (red arrow in Figure 6) in the indoor localization periods, thus finishing building NLOS man-made dynamic and flexible scenarios. The man-made scenarios were divided into four patterns: slow speed, normal speed, running speed (or sliding forward), and random mode. Among them, the slow speed was far lower than the normal speed. According to our measurements, the slow speed was around 0.5-0.6 m/s. The normal walking speed was about 1.2-2 m/s. The running speed or sliding forward was about 4-7 m/s. It was difficult for the volunteers to achieve full speed forward like in outside environments due to the limitations of the indoor area. As for the last mode, the system selected a random number from 1, 2, and 3 first, and then determined the action pattern under this mode according to the number obtained equiprobably. To finish the dual-receiving process, PCB boards were required. Referring to [21], the PCB circuit board contained an electrodeless capacitor, TDA2030A audio power amplifier, DDS module, TPS5430 adjustable voltage module, and MP1584 EN buck converter. The piezoelectric tweeter in each acoustic anchor of the dual-receiving structure could be fixed with specific devices or powerful glue without a disgusting smell. The signal acquisition module on the PCB board needed to handle the acquired acoustic signal, so as to ensure that the protection interval of the indoor localization system in a single localization loop was long enough to complete all processing procedures. The acoustic signal delay gain or the generation time processed by the RSS selecting mechanism in the classification module turned out to be essential under this circumstance. Then, it was expected to complete the wav file cutting at the main anchor. This part could be determined based on delay gain or relative gain according to the implementation schemes of the system [11; 22].