Collaboration with Cellular Networks for RFI Cancellation at Radio Telescope

TL;DR

This paper introduces a collaborative RFI cancellation method using eigenspaces derived from both telescope and transmitter signals, significantly reducing interference from cellular networks in radio astronomy observations.

Contribution

The work presents a novel eigenspace-based RFI cancellation technique that adapts to changing signal statistics, improving over traditional fixed-characterization methods.

Findings

Achieved 89.04% RFI removal from cellular signals.

Enhanced data usability by reducing interference in radio telescope observations.

Validated effectiveness with real astronomical and simulated LTE signals.

Abstract

The growing need for electromagnetic spectrum to support the next generation (xG) communication networks increasingly generate unwanted radio frequency interference (RFI) in protected bands for radio astronomy. RFI is commonly mitigated at the Radio Telescope without any active collaboration with the interfering sources. In this work, we provide a method of signal characterization and its use in subsequent cancellation, that uses Eigenspaces derived from the telescope and the transmitter 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 in communication systems. We have presented effectiveness of this collaborative method using real-world astronomical signals and practical simulated LTE signals (downlink and uplink) as source of RFI along with propagation conditions based on preset benchmarks and standards. Through our analysis and simulation using these signals, we are able to remove 89.04% of the RFI from cellular networks, which reduces excision at the Telescope and capable of significantly improving throughput as corrupted time frequency bins data becomes usable.