Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Terrestrial-Satellite Spectrum Sharing in the Upper Mid-Band with Interference Nulling

Seongjoon Kang, Giovanni Geraci, Marco Mezzavilla, Sundeep Rangan

TL;DR

This paper investigates the interference dynamics in terrestrial-satellite coexistence scenarios and introduces a novel beamforming approach that leverages available ephemeris data for dynamic interference mitigation and offers a promising pathway for efficient spectrum sharing in the upper mid-band.

Abstract

The growing demand for broader bandwidth in cellular networks has turned the upper mid-band (7-24 GHz) into a focal point for expansion. However, the integration of terrestrial cellular and incumbent satellite services, particularly in the 12 GHz band, poses significant interference challenges. This paper investigates the interference dynamics in terrestrial-satellite coexistence scenarios and introduces a novel beamforming approach that leverages available ephemeris data for dynamic interference mitigation. By establishing spatial radiation nulls directed towards visible satellites, our technique ensures the protection of satellite uplink communications without markedly compromising terrestrial downlink quality. Through a practical case study, we demonstrate that our approach maintains the satellite uplink signal-to-noise ratio (SNR) degradation under 0.1 dB and incurs only a negligible SNR penalty for the terrestrial downlink. Our findings offer a promising pathway for efficient spectrum sharing in the upper mid-band, fostering a concurrent enhancement in both terrestrial and satellite network capacity.

Terrestrial-Satellite Spectrum Sharing in the Upper Mid-Band with Interference Nulling

TL;DR

This paper investigates the interference dynamics in terrestrial-satellite coexistence scenarios and introduces a novel beamforming approach that leverages available ephemeris data for dynamic interference mitigation and offers a promising pathway for efficient spectrum sharing in the upper mid-band.

Abstract

The growing demand for broader bandwidth in cellular networks has turned the upper mid-band (7-24 GHz) into a focal point for expansion. However, the integration of terrestrial cellular and incumbent satellite services, particularly in the 12 GHz band, poses significant interference challenges. This paper investigates the interference dynamics in terrestrial-satellite coexistence scenarios and introduces a novel beamforming approach that leverages available ephemeris data for dynamic interference mitigation. By establishing spatial radiation nulls directed towards visible satellites, our technique ensures the protection of satellite uplink communications without markedly compromising terrestrial downlink quality. Through a practical case study, we demonstrate that our approach maintains the satellite uplink signal-to-noise ratio (SNR) degradation under 0.1 dB and incurs only a negligible SNR penalty for the terrestrial downlink. Our findings offer a promising pathway for efficient spectrum sharing in the upper mid-band, fostering a concurrent enhancement in both terrestrial and satellite network capacity.
Paper Structure (9 sections, 8 equations, 7 figures, 1 table)

This paper contains 9 sections, 8 equations, 7 figures, 1 table.

Table of Contents

  1. Introduction
  2. Single Victim Satellite in a LOS Channel
  3. Proposed Interference Nulling Technique
  4. Case Study and Performance Evaluation
  5. System Model and Methodology
  6. Key Performance Indicators
  7. Coexistence Evaluation Without Interference Nulling
  8. Performance Evaluation of Interference Nulling
  9. Conclusion

Figures (7)

  • Figure 1: Illustration of the interference caused by the cellular downlink to the satellite uplink through BS antenna sidelobes.
  • Figure 2: Change in the total BS-to-satellite propagation loss caused by accounting for the antenna element gain as a function of the LEO satellite elevation angle $\theta$ for an azimuth angle fixed to $\phi=0^\circ$.
  • Figure 3: Beamforming gains in beam space for an $8 \times 8$ BS URA.
  • Figure 4: Rural area near Boulder, CO, used for our case study.
  • Figure 5: Computation of satellite multi-path channels: (i) satellite coordinates $(\theta^{t}, \phi^{t})$ at time $t$ are tracked via ephemeris data; (ii) ray-tracing is employed to pre-compute the multi-path channels for each set of coordinates in the look-up table; and (iii) over time the multi-path channel instances are extracted from the look-up table.
  • ...and 2 more figures