Spectrum Sharing via Collaborative RFI Cancellation for Radio Astronomy

Abstract

Radio frequency Interference (RFI) from cellular and other communication networks is commonly mitigated at the Radio Telescope without any active collaboration with the interfering sources. The expanding Universe and simultaneous proliferation of Earth based and LEO communication infrastructure is causing unprecedented RFI that require collaborative strategies to maintain the scientific and societal goal of each. In this work, we provide a method of signal characterization and its use in subsequent cancellation, that uses Eigenspaces derived from the astronomical and the RFI signals. This is different from conventional time-frequency domain analysis, which is limited to fixed characterizations (e.g., complex exponential in Fourier methods) that cannot adapt to the changing statistics (e.g., autocorrelation) of the RFI, typically observed from communication systems. Through our analysis and simulation using real-world astronomical signals, we are able to remove RFI from cellular networks by 89.04%, which reduces excision at the Telescope.