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arXiv · 2607.25562

Joint Channel Estimation and Data Detection for Multi-LEO-Satellite Cell-Free OTFS Uplinks

Gangle Sun·Tianhao Liu·Jun Tian·Xin Cheng·Jian Wu·Jinfang Jiang·Wenjin Wang·Shi Jin·Guangjie Han
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Abstract

Cell-free networks formed by multiple low Earth orbit (LEO) satellites offer a promising architecture for ubiquitous connectivity, but their cooperative reception is challenged by link-dependent residual delays and Doppler shifts. This paper investigates joint channel estimation and data detection (JCEDD) for multi-LEO-satellite cell-free orthogonal time frequency space (OTFS) uplinks. The JCEDD problem is formulated as a structured bilinear inference problem involving link-specific sparse beam--delay--Doppler channels and a multiuser data vector. We develop a low-complexity hierarchical JCEDD receiver in which all satellites first perform local JCEDD, and their observations and local estimates are then aggregated at a central satellite for cooperative refinement. Computational complexity is reduced by restricting channel estimation to coarse-information-aided local beam--delay--Doppler regions and evaluating the required forward and adjoint operations in a matrix-free manner. Simulation results validate the channel-estimation accuracy and data-detection reliability of the proposed JCEDD receiver.

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Gangle Sun, Tianhao Liu, Jun Tian, Xin Cheng, Jian Wu, Jinfang Jiang, Wenjin Wang, Shi Jin, Guangjie Han. 2026-07-28. Joint Channel Estimation and Data Detection for Multi-LEO-Satellite Cell-Free OTFS Uplinks. https://arxiv.org/abs/2607.25562

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