EPFL-REMNet: Efficient Personalized Federated Digital Twin Towards 6G Heterogeneous Radio Environment
Peide Li, Liu Cao, Lyutianyang Zhang, Dongyu Wei, Ye Hu, Qipeng Xie
TL;DR
This work tackles the challenge of building a high-fidelity Radio Environment Map (REM) digital twin for 6G under strong data heterogeneity and limited uplink bandwidth. It introduces EPFL-REMNet, a co-designed framework that couples a shared backbone with client-specific heads and a multi-stage communication compression pipeline to achieve superior REM fidelity while drastically reducing uplink traffic. Across light, medium, and heavy Non-IID scenarios, EPFL-REMNet outperforms standard FedAvg and recent baselines, demonstrates Pareto-optimal fidelity-communication trade-offs, and shows robust fairness across base stations and long-tail clients. The findings highlight the value of jointly optimizing personalization and communication efficiency to enable scalable, reliable digital twins in heterogeneous wireless environments.
Abstract
Radio Environment Map (REM) is transitioning from 5G homogeneous environments to B5G/6G heterogeneous landscapes. However, standard Federated Learning (FL), a natural fit for this distributed task, struggles with performance degradation in accuracy and communication efficiency under the non-independent and identically distributed (Non-IID) data conditions inherent to these new environments. This paper proposes EPFL-REMNet, an efficient personalized federated framework for constructing a high-fidelity digital twin of the 6G heterogeneous radio environment. The proposed EPFL-REMNet employs a"shared backbone + lightweight personalized head" model, where only the compressed shared backbone is transmitted between the server and clients, while each client's personalized head is maintained locally. We tested EPFL-REMNet by constructing three distinct Non-IID scenarios (light, medium, and heavy) based on radio environment complexity, with data geographically partitioned across 90 clients. Experimental results demonstrate that EPFL-REMNet simultaneously achieves higher digital twin fidelity (accuracy) and lower uplink overhead across all Non-IID settings compared to standard FedAvg and recent state-of-the-art methods. Particularly, it significantly reduces performance disparities across datasets and improves local map accuracy for long-tail clients, enhancing the overall integrity of digital twin.
