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arXiv · 2606.00701

Rethinking NB-IoT Downlink Synchronization for LEO-NTN: A Novel Overhead Reduction Method and Measurement-Based Evaluation

Ömer Lütfü Karakelle·Erhan Karakoca·Bengü Bilgiç Keskin·İbrahim Hökelek·Ali Görçin·Halim Yanikomeroglu
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Abstract

Narrowband Internet of Things (NB-IoT) over non-terrestrial networks (NTN) is a key enabler for massive Internet of Things (IoT) in 6G, but in low Earth orbit (LEO) scenarios, large and time-varying Doppler shifts generate carrier frequency offset (CFO) beyond the correction range of standard user equipment (UE), making initial downlink synchronization a major bottleneck. This paper analyzes Doppler characteristics in realistic NB-IoT LEO scenarios, reviews Doppler mitigation strategies, and proposes a standard-compliant, low-overhead search-space optimization method for downlink acquisition. Results under realistic LEO conditions with real-time measurements show reduced acquisition overhead while maintaining synchronization reliability, supporting NB-IoT adaptation to 6G NTN deployment.

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Ömer Lütfü Karakelle, Erhan Karakoca, Bengü Bilgiç Keskin, İbrahim Hökelek, Ali Görçin, Halim Yanikomeroglu. 2026-05-30. Rethinking NB-IoT Downlink Synchronization for LEO-NTN: A Novel Overhead Reduction Method and Measurement-Based Evaluation. https://arxiv.org/abs/2606.00701

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