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arXiv · 2609.06537

UAV Fluid-Antenna Channel Acquisition under Intra-Scan Channel Aging

Yuanhui Wu·Hao Jiang·Liang Wu·Zaichen Zhang
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Abstract

Sequential sounding in UAV fluid-antenna systems (FASs) provides additional spatial information but delays transmission, causing earlier channel observations to age. This paper addresses the resulting information--freshness tradeoff by jointly determining where to probe and when to stop under blockwise hardware constraints. A dynamic Karhunen--Lo\`eve estimator aligns asynchronous measurements with the transmission state, covariance information gain selects feasible probe locations, and an age-discount identity with a local one-more-slot condition characterizes the covariance-level balance between information and freshness. Paired simulations show that temporal alignment recovers most of the lower-tail reliability lost by static stacking, covariance-aware probing ranks highest numerically among the evaluated policies, and optimized one-slot sounding becomes statistically competitive with two-slot alternatives at the highest tested mobility. Within the evaluated schedule family, increasing mobility shifts the competitive operating region toward shorter scans, supporting joint probe-placement and sounding-duration design.

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Yuanhui Wu, Hao Jiang, Liang Wu, Zaichen Zhang. 2026-09-06. UAV Fluid-Antenna Channel Acquisition under Intra-Scan Channel Aging. https://arxiv.org/abs/2609.06537

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