A New Spatial Block-Correlation Model for Fluid Antenna Systems Ramírez Espinosa, Pablo Morales-Jimenez, David Wong, Kai Kit Powered by position-flexible antennas, the emerging fluid antenna system (FAS) technology is postulated as a key enabler for massive connectivity in 6G networks. The free movement of antenna elements enables the opportunistic minimization of interference, allowing several users to share the same radio channel without the need of precoding. However, the true potential of FAS is still unknown due to the extremely high spatial correlation of the wireless channel between very close-by antenna positions. To unveil the multiplexing capabilities of FAS, proper (simple yet accurate) modeling of the spatial correlation is prominently needed. Realistic classical models such as Jakes’s are prohibitively complex, rendering intractable analyses, while state-of-the-art approximations often are too simplistic and poorly accurate. Aiming to fill this gap, we here propose a general framework to approximate spatial correlation by block-diagonal matrices, motivated by the well-known block fading assumption and by statistical results on large correlation matrices. The proposed block-correlation model makes the performance analysis possible, and tightly approximates the results obtained with realistic models (Jakes’s and Clarke’s). Our framework is leveraged to analyze fluid antenna multiple access (FAMA) systems, evaluating their performance for both one- and two-dimensional fluid antennas. 2024-10-18T10:16:41Z 2024-10-18T10:16:41Z 2024-08-05 journal article P. Ramírez-Espinosa, D. Morales-Jimenez and K. -K. Wong, "A New Spatial Block-Correlation Model for Fluid Antenna Systems," in IEEE Transactions on Wireless Communications, doi: 10.1109/TWC.2024.3434509 https://hdl.handle.net/10481/96099 10.1109/TWC.2024.3434509 eng http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional Institute of Electrical and Electronics Engineers (IEEE)