Bispectra of simulated GPS data for potential RFI mitigation

Abstract

Radio telescopes are becoming more powerful, with increased sensitivity to both astronomical and interfering sources. Various interference mitigation techniques exist, however they could be harmful to the signal of interest, thus it is important to develop new techniques. Majority of radio astronomical sources are considered to have a Gaussian distribution which are fully characterised using second-order power statistics. Higher-order statistics is a tool that can suppress Gaussian noise, therefore if interference have energy in higher domains it could form the basis for a new mitigation technique. This work uses a third-order statistic, the bispectrum, to conduct analysis on global positioning system (GPS) signals. It is found that one of the in-phase components of GPS signals has energy in the bispectrum.