Spectral Coexistence of Wi-Fi Networks with Radar Systems

Abstract

With crowded frequency bands and high mobile data demand, Wi-Fi networks would benefit from more available spectrum. Underutilized radar spectrum due to the directionality and rest periods of rotating radar makes it a viable candidate for spectrum sharing with Wi-Fi. But if operating on the same bands, radar signals would interfere with Wi-Fi receivers, reducing WLAN performance. This thesis investigates Wi-Fi network performance when sharing spectrum with radar. Both link and system level software simulators were developed to study the effects of coexistence, providing highly configurable platforms with repeatable results. The link simulator comprises a signal level model of baseband Wi-Fi transmitter and receiver chains with injected radar pulse interference, and is used to determine the effects of radar interference on PHY communication performance. The ns-3 network simulator is used for full Wi-Fi system performance analysis, with enhancements added to model radar interference using mapped link simulation results. The source code for both simulators will be hosted on the UW Fundamentals of Networking Laboratory website at: http://depts.washington.edu/funlab/. From analyzing the simulation results, insight was gained about the impact of radar interference on Wi-Fi and how different system parameters affect the performance. Techniques are proposed to mitigate Wi-Fi performance degradation amid radar interference.