Resilient Channel Charting Under Varying Radio Link Availability

Pirkl J, Ott J, Stahlke M, Yammine G, Feigl T, Mutschler C (2025)

Publication Type: Conference contribution

Publication year: 2025

Journal

Conference Record of the Asilomar Conference on Signals, Systems and Computers Institute of Electrical and Electronics Engineers

Publisher: IEEE Computer Society

Pages Range: 886-890

Conference Proceedings Title: Conference Record - Asilomar Conference on Signals, Systems and Computers

Event location: Pacific Grove, CA, USA

ISBN: 9798331587451

DOI: 10.1109/IEEECONF67917.2025.11443931

Abstract

Channel charting (CC) has become a key technology for RF-based localization, enabling unsupervised radio fingerprinting, even in non line of sight scenarios, with a minimum of reference position labels. However, most CC models assume fixed-size inputs, such as a constant number of antennas or channel measurements. In practical systems, antennas may fail, signals may be blocked, or antenna sets may change during handovers, making fixed-input architectures fragile. Existing radio-fingerprinting approaches address this by training separate models for each antenna configuration, but the resulting training effort scales prohibitively with the array size.We propose Adaptive Positioning (AdaPos), a CC architecture that natively handles variable numbers of channel measurements. AdaPos combines convolutional feature extraction with a transformer-based encoder using learnable antenna identifiers and self-attention to fuse arbitrary subsets of CSI inputs. Experiments on two public real-world datasets (SISO and MIMO) show that AdaPos maintains state-of-the-art accuracy under missing-antenna conditions and replaces roughly 57 configuration-specific models with a single unified model. With AdaPos and our novel training strategies, we provide resilience to both individual antenna failures and full-array outages.

Authors with CRIS profile

Tobias Feigl
Christopher Mutschler

Involved external institutions

Fraunhofer-Institut für Integrierte Schaltungen (IIS) DE Germany (DE)

How to cite

APA:

Pirkl, J., Ott, J., Stahlke, M., Yammine, G., Feigl, T., & Mutschler, C. (2025). Resilient Channel Charting Under Varying Radio Link Availability. In Michael B. Matthews (Eds.), Conference Record - Asilomar Conference on Signals, Systems and Computers (pp. 886-890). Pacific Grove, CA, USA: IEEE Computer Society.

MLA:

Pirkl, Jonas, et al. "Resilient Channel Charting Under Varying Radio Link Availability." Proceedings of the 59th Asilomar Conference on Signals, Systems and Computers, ACSSC 2025, Pacific Grove, CA, USA Ed. Michael B. Matthews, IEEE Computer Society, 2025. 886-890.

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