Energy-Efficient Over-the-Air Federated Learning via Pinching Antenna Systems
Saba Asaad, Ali Bereyhi
TL;DR
This work addresses energy-efficient over-the-air federated learning (OTA-FL) in wireless networks where large-scale fading degrades aggregation quality. It proposes a pass-assisted server architecture (PASS) and a low-complexity, computation-rate–driven optimization that jointly tunes PASS locations, device scheduling, and transmit scalars to minimize energy while meeting a target aggregation accuracy. The core contributions are: (i) a PASS-based OTA-FL formulation that links energy to the computation rate $\mathcal{R}_{comp}$, (ii) a two-tier alternating-optimization algorithm combining projection-based PASS tuning, Dinkelbach–DC power scaling, and step-wise scheduling, and (iii) numerical results showing substantial energy reduction compared with a fully digital MIMO server, and robustness to region size. The results demonstrate that PASS can provide substantial energy efficiency gains for distributed learning in next-generation wireless systems and motivate further exploration of MIMO-PASS extensions.
Abstract
Pinching antennas systems (PASSs) have recently been proposed as a novel flexible-antenna technology. These systems are implemented by attaching low-cost pinching elements to dielectric waveguides. As the direct link is bypassed through waveguides, PASSs can effectively compensate large-scale effects of the wireless channel. This work explores the potential gains of employing PASSs for over-the-air federated learning (OTA-FL). For a PASS-assisted server, we develop a low-complexity algorithmic approach, which jointly tunes the PASS parameters and schedules the mobile devices for minimal energy consumption in OTA-FL. We study the efficiency of the proposed design and compare it against the conventional OTA-FL setting with MIMO server. Numerical experiments demonstrate that using a single-waveguide PASS at the server within a moderately sized area, the required energy for model aggregation is drastically reduced as compared to the case with fully-digital MIMO server. This introduces PASS as a potential technology for energy-efficient distributed learning in next generations of wireless systems.
