Electronic beamforming
Reliable communication links with unmanned aerial vehicles (UAVs) are of key importance for a large range of applications. AIT is active in the design an control of electronic antenna arrays for multi-beam forming to keep a reliable link to a swarm of UAVs.
Antenna arrays allow the controlled transmission of radio signals in a defined direction as well as the focusing on a spatial area. Hence, AIT is investigating this method using the AIT software defined radio lab for reliable communication and sensing use cases for time critical scenarios.
Wide distributed massive MIMO systems
Distributed massive MIMO systems are highly interesting for dependable wireless communication systems. The small-footprint and low-power antenna elements/radio units (RU) can be sparsely distributed inside a building or within a larger geographic area reducing the distance from RU to the user by a factor of 10, i.e., reducing the power consumption by two orders of magnitude.
[Loe23a] D. Löschenbrand, M. Hofer, L. Eller, M. Rupp, and T. Zemen, “Machine learning-based channel prediction for widely distributed massive MIMO with real-world data,” in Asilomar Conference on Signals, Systems, and Computers (ASILOMAR), Pacific Grove, CA, USA, October 2023, invited.
[Loe23] D. Löschenbrand, M. Hofer, and T. Zemen, “Spectral efficiency of time-variant massive MIMO using Wiener prediction,” IEEE Communication Letters, vol. 27, no. 4, pp. 1225 - 1229, April 2023.
[Loe22] D. Löschenbrand, M. Hofer, L. Bernadó, S. Zelenbaba, and T. Zemen, “Towards cell-free massive MIMO: A measurement-based analysis,” IEEE Access, vol. 10, pp. 89232 - 89247, August 2022.
AIT has built a real-time capable software-defined radio (SDR) system whose antennas enable coherent signal generation and reception over an aperture of 100m. 6G distributed MIMO measurements with mobile terminals [Loe22] have been carried out based on this testbed and signal processing algorithms for mobile users [Loe23, Loe23a] have been developed.
