Evaluating Time Occupancy and Time-Scales in Interference Testing with Pulse-Modulated Noise

We present experimental results investigating the utility of pulse-modulated noise (PMN) for general-purpose, systematic interference testing. Time-domain interference vulnerabilities are examined by modifying the PMN duty cycle, which controls time occupancy, and the PMN period, which modifies the time-scale. The PMN waveform class that we utilize depends on only two parameters, making it far simpler than real-world communication signals and easier to generate. We perform experimentation with a conducted interference testbed that uses a consumer off-the-shelf (COTS) IEEE 802.11n Wireless Local Area Network (WLAN) Wi-Fi link as the victim system. Comparisons are also made between PMN and measured long-term evolution (LTE) and Wi-Fi signals of corresponding time occupancies to assess if realistic interference impacts are generated by PMN. We find that time occupancy is a strong predictor of interference impacts, but that time-scale and time correlations can also be relevant factors in some circumstances. Overall, our findings support PMN as a useful class of artificial test waveforms for interference testing that can be used to characterize a wide range of interference vulnerabilities on a bidirectional communication link.