SIM-Empowered Architecture: A Wave-Domain Framework Enabling Sustainable and Inclusive ISAC-Centric 6G Transceivers

Objective

The emergence of sixth-generation (6G) networks demands transceiver architectures that jointly enable communication, localization, and sensing while supporting societal goals of sustainability and inclusiveness. Conventional digital and hybrid multiple-input multiple-output (MIMO) approaches rely on numerous RF chains and power-hungry components, making them costly, energy-inefficient, and difficult to scale for large-array deployments. Stacked intelligent metasurfaces (SIMs), formed by vertically stacking multiple reconfigurable intelligent surface (RIS) layers within the transceiver front-end, offer a compelling alternative by shifting signal processing from the baseband to the wave domain, enabling parallel operations at the speed of light. Yet their potential in integrated sensing and communication (ISAC) systems remains largely unexplored. The SIMPACT-6G project addresses this gap through three work packages: (i) developing physically consistent models that capture electromagnetic interactions in SIM-based ISAC transceivers, (ii) designing a unified wave-domain framework for parallel signal processing, and (iii) validating performance in the FR3 band (7–24 GHz) under emerging 6G scenarios, in line with societal objectives. These advances will deliver scalable, energy-efficient ISAC transceivers, strengthen Europe’s leadership and strategic autonomy in 6G, accelerate standardization efforts, and enable affordable deployments in underserved regions, thereby advancing digital inclusion and supporting the EU’s Green Deal and Digital Decade objectives.