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Abstract Sixth-generation wireless networks will aggregate higher-than-ever mobile traffic into ultra-high capacity backhaul links, which could be deployed on the largely untapped spectrum above 100 GHz. Current regulations however prevent the allocation of large contiguous bands for communications at these frequencies, since several narrow bands are reserved to protect passive sensing services. These include radio astronomy and Earth exploration satellites using sensors that suffer from harmful interference from active transmitters. Here we show that active and passive spectrum sharing above 100 GHz is feasible by introducing and experimentally evaluating a real-time, dual-band backhaul prototype that tracks the presence of passive users (in this case the NASA satellite Aura) and avoids interference by automatically switching bands (123.5–140 GHz and 210–225 GHz). Our system enables wide-band transmissions in the above-100-GHz spectrum, while avoiding harmful interference to satellite systems, paving the way for innovative spectrum policy and technologies in these crucial bands.
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Testbed for Radio Astronomy Interference Characterization and Spectrum Sharing Research
As radio spectrum becomes increasingly scarce, coexistence and bidirectional sharing between active and passive systems becomes a crucial target. In the past, spectrum regulations conferred radio astronomy a status on par with active services, thereby protecting their extreme sensitivity against any harmful interference. However, passive systems are likely to lose exclusive allocations as capacity constraints for active systems increase. The resulting increase in ambient radio frequency noise from various terrestrial and non-terrestrial emitters can only be mitigated with informed collaboration between active and passive users. While coexistence using time-division spectrum access has been proposed in the past, a more dynamic approach following the CBRS sharing principle promises greater spectral occupancy and efficiency, enabled by a spectrum access system capable of constantly monitoring the ambient RF environment. Instead of simply minimizing the potential for any ”harmful” interference to passive users, the goal is to use good engineering to enable sharing between active and passive users. To this end, this research created a Software Defined Radio (SDR)-based testbed at the the Hat Creek Radio Observatory to quantitatively characterize the radio-frequency environment, and flag potential sources of radio frequency interference in the vicinity of the Allen Telescope Array. Sensor validation was carried out via data analysis of I/Q data collected in well-characterized RF bands. Results so far from ground and drone-based surveys are consistent with the expected sources of interference, based on both the deployment of static RF transmitters in the Hat Creek/Redding area as well as the interference detected in telescope observations themselves.
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- PAR ID:
- 10519033
- Publisher / Repository:
- IEEE
- Date Published:
- ISBN:
- 978-1-6654-9032-0
- Page Range / eLocation ID:
- 1 to 16
- Subject(s) / Keyword(s):
- Radio Astronomy Interference Cognitive Radio SDR Noise Instrumentation
- Format(s):
- Medium: X
- Location:
- Big Sky, MT, USA
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/AERO55745.2023.10115653
