# ROAD Statistics-Based Noise Detection for DME Mitigation in LDACS
## 5 Results and Discussions
The false detection caused due to the amplitude-based sensing for an SNR value of 15 dB is visible (sample values between 2500 and 3000) in Figure 9.  
The amplitude of the DME interference signal, amplitude of the received signal along with the threshold value for sensing and the calculated ROAD values of the received signal are plotted in Figure 9. The signals are plotted together to figure out how both amplitude and ROAD value-based sensing accomplishes the detection of DME interference pulses. It can be observed from Figures 9 and 10 that the ROAD values of the received signal is  
Figure 8: Standard DME pulse pair. Figure 7: Performance of conventional pulse blanking technique vs. without DME interference and with DME interference. An inclusive analysis of amplitude-based sensing and ROAD value-based sensing at low and high SNR levels has been portrayed in Figures 12 and 13, respectively. The characterization of different probability measures ( accuracy, false detection and missed detection) are also analyzed in Figures 14-16. The findings from the comparative study of amplitude-based sensing and ROAD value-based sensing are as follows:  
1. The number of false detections in amplitude-based sensing is more at a low SNR level of operation than high SNR values. 2. The number of false detections due to ROAD value-based sensing is always less (whether in high SNR level or in low SNR level) than amplitude-based sensing. 3. The performance of ROAD value-based sensing is almost the same in both low and high SNR levels. 4. ROAD value-based sensing shows some amount of missed detection as in between the samples 1000 and 1500 (Figure 13). The same sample is not lost in amplitude-based detection as it crosses the threshold value. 5. The probability of false detection that occurs in ROAD value-based sensing is observed to be always less than from amplitude-based sensing for all the SNR values under consideration. The probability of false detection is found to be decreased with an increase in SNR values due to the reduction in noise level (Figure 15). 6. The probability of missed detection is observed to increase with an increase in SNR levels in the case of amplitude-based sensing (Figure 16). 7. The probability of missed detection is found to be slightly decreasing with an increase in SNR values for ROAD value-based detection (Figure 16). 8. The probability of missed detection is found to be more for ROAD value-based detection than amplitude-based sensing. 9. Regardless of the elevated number of missed detections that occurred in ROAD value-based sensing, the method showed high accuracy in detection compared to conventional amplitude-based sensing (Figure 14). The above mentioned (2, 3, 5 and 9) statements, which are realized from the obtained results, affirm that ROAD value-based sensing is admirable in comparison to amplitude value-based sensing in detecting DME interference. Furthermore, the characterization of the ROAD statistic-based detection for different threshold ROAD values and SNRs has been performed. The results are as displayed in Figures 17-19. It has been observed that the probability of false detection decreases with an increase in threshold values (Figure 17) and the probability of missed detection increases with an increase in threshold value, Figure 18. Hence, there is a trade-off between false detection and missed detection for different values of threshold. Hence, to identify the optimum threshold, we have analyzed the variation in probability of correct detection  
Figure 11: DME interference (**Top**), amplitude of the received signal without interference mitigation (**Middle**) and ROAD value of the received signal (**Bottom**) for an SNR of 15 dB. (accuracy) for different threshold values. From Figure 19, it is noted that the accuracy in ROAD value-based sensing increases from threshold ROAD value 5 to 8. The reason for this nature is the considerable reduction in false detection occurring in ROAD value-based sensing. Further, the performance starts diminishing from 8 to 12.