Spatial Multiplexing Fluid Antenna Systems

The sixth-generation (6G) of wireless networks requires a paradigm shift beyond the limitations of current fixed-position antenna arrays. While the emerging Fluid Antenna System (FAS) offers unprecedented reliability by selecting a single optimal antenna port, this focus on diversity is a strategic dead end for 6G's extreme capacity goals, as it cannot achieve spatial multiplexing (SM).This project, Spatial Multiplexing Fluid Antenna Systems (SM-FAS), pioneers a fundamental pivot to unlock massive throughput. It addresses the critical question: how can an optimal subset of antenna ports be activated simultaneously to create parallel data streams?To realise this vision, this fellowship will execute a holistic research programme progressing from theory to experimental proof-of-concept. The objectives are: (1) To establish the first comprehensive theoretical framework for SM-FAS, deriving its fundamental performance limits and scaling laws. (2) To design novel, low-complexity algorithms for the joint optimisation of port selection and beamforming. (3) To create a practical framework for adaptive control of the diversity-multiplexing tradeoff (DMT). (4) To build and experimentally validate the world's first SM-FAS prototype capable of demonstrating spatial multiplexing.The project will deliver the foundational theory, practical algorithms, and hardware validation needed to establish SM-FAS as a core 6G enabling technology. This will secure Europe’s technological leadership, generate significant scientific and economic impact, and provide the researcher with a unique training environment to become a future leader in wireless communications.