# Extending the Coverage of IEEE 802.15.4z HRP UWB Ranging
## 4 Experimental Results and Discussion
### Maximum Ranging Experiment According to PSR and PAC Size  
The second experiment was conducted to identify the maximum communication distance and stable ranging measurement conditions in an actual sports field environment. The measurement environment was the athletic field of Kookmin University in Seoul, Republic of Korea, as shown in Figure 12. The RF environment at the athletic field was verified to be free of active RF sources, and no significant interference was expected, as WiFi 6E operation is restricted to indoor use under local regulations in Korea. The maximum ranging distance satisfying a packet reception success rate of 90% was measured by changing parameters such as the PSR and PAC counts, and the distance values at that time were organized as median values. Through this process, it was possible to confirm how the processing gain according to the PSR and PAC counts affected the actual long-distance ranging performance. The experimental conditions are as shown in Table 4, and the same SP0 packet format as that in the first experiment was used, but the ranging measurement was performed with the DS-TWR method. The preamble used low-speed data transmission (850 kbps) to be suitable for long-distance ranging. Through these settings, it was possible to confirm how much the processing gain in the preamble contributed to the actual maximum ranging measurement. The coverage of ranging satisfying a success rate of 90% or more was compared and analyzed by changing the PSR and PAC values step by step. Figure 13 shows the results for the maximum ranging distance according to the PAC size and PSR length. As can be seen in the figure, the interaction between the PACs and PSRs had a significant impact on the ranging performance. The ranging performance comparison according to the change in PAC size showed excellent performance in the order of 32, 16, 4, and 8 PACs, and in particular, the lowest overall performance was shown when the PAC size was 8. It was confirmed that the maximum ranging performance improved by 2-3 times just by changing the PAC size from 8 to 16. This confirms that the processing gain secured by the increase in PAC size greatly contributes to longer ranging coverage. In addition, Figure 13 shows that the link performance of the SYNC and DP was balanced at 256 PSRs, as analyzed in Figure 10, and there was no significant change even if the PSR count was increased beyond that. Therefore, this shows that the operating range  
Figure 11: Experiment results of HRP UWB at 10 m using DW3000 UWB module: (**a**) low-speed (850 kbps) data transmission and (**b**) high-speed (6.8 Mbps) data transmission. could be further expanded through the gating gain after fixing the PSR count to 256. In an experiment where the output was increased after fixing the PSR count to 256, it was confirmed that stable ranging measurement was possible at a distance of more than 300 m.  
As shown in Figure 13, the ranging coverage increased as the PSR count increased in the order of [64; 128; 256; 512; 1024; 4096]. However, the PSR effect was found to be interrelated with the PAC size. Specifically, when the PAC size was set to four or eight, the distance measurement performance tended to remain below 100 m overall. On the other hand, when the PAC size was set to 16 or 32, the distance measurement capability was significantly improved as the PSR count increased. In particular, the performance improvement effect was remarkable when the PSR count increased in the order of [64; 128; 256], and the best distance measurement performance was observed overall when the PAC size was set to 32. However, the performance improvement due to the increase from 16 to 32 was relatively limited compared with when the PAC size was increased from 8 to 16. Through this experiment, it was found that increasing the PAC and PSR counts significantly improved the link margin in the SHR section, leading to a significant improvement in the maximum distance measurement.