Out-of-Band Interference Management to Protect Radio Astronomy

Radio astronomy has revolutionized our understanding of the cosmos by detecting and analyzing weak radio emissions from celestial sources using highly sensitive instruments. The rapid expansion of 5G networks near these passive radio applications poses a substantial risk of out-of-band interference, potentially violating their stringent interference thresholds and compromising the integrity of astronomical observations. This paper explores methodologies to effectively manage out-of-band interference from 5G base stations (BSs) to radio astronomy sites. We design a novel power control algorithm to maximize both the number of active BSs and their transmit powers while ensuring the interference threshold at the radio astronomy site is not violated. We compare it with state-of-the-art approaches: Radio Quite Zone (RQZ) and move list. Through simulation experiments on real-world VLBA, we demonstrate that the power control algorithm achieves the smallest number of deactivated BSs by utilizing a lower power level. However, the move list algorithm achieves the smallest uncovered region by using the maximum transmit power. Both the power control and the move list algorithms significantly outperform the RQZ in terms of the number of active BSs and coverage.