Performance Comparison of Space-Constrained Antenna Arrays for MU-MIMO L-band Aircraft-Ground Links

Kurzfassung

This paper investigates various antenna array configurations for multiuser multiple input multiple output (MU-MIMO) in L-band air-ground communications. We consider multiple aircraft transmitting simultaneously to a ground station equipped with an antenna array. Specifically, we evaluate three configurations: uniform planar array (UPA), uniform circular array (UCA), and uniform Fermat spiral array (UFSA). Our focus is on the deployment challenges arising from the physical size of these arrays in the L-band. In this context, we evaluate the deployment under a physical space-constraint, defined as a fixed square area at the ground station. Within this area, we determine the maximum number of antenna elements that can be integrated for each specific configuration, while maintaining a half-wavelength spacing between the elements. Consequently, each array configuration uses a different number of antenna elements but fits within the same space. Our results show that both the UFSA and UPA configurations yield nearly identical performance, though the UFSA configuration necessitates fewer antenna elements. In contrast, the UCA maintains performance parity only up to a spatial-constraint of 1 m^2, after which its efficacy degrades significantly. Notably, at 1 m^2, UCA achieves comparable performance using approximately half the antenna elements of the other configurations.