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arXiv · 2503.00980

RSSI Positioning with Fluid Antenna Systems

Wenzhi Liu·Zhisheng Rong·Xiayue Liu·Yufei Jiang·Xu Zhu
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Abstract

We introduce a novel received signal strength intensity (RSSI)-based positioning method using fluid antenna systems (FAS), leveraging their inherent channel correlation properties to improve location accuracy. By enabling a single antenna to sample multiple spatial positions, FAS exhibits high correlation between its ports. We integrate this high inter-port correlation with a logarithmic path loss model to mitigate the impact of fast fading on RSSI signals, and derive a simplified multipoint positioning model based on the established relationship between channel correlation and RSSI signal correlation. A maximum likelihood estimator (MLE) is then developed, for which we provide a closed-form solution. Results demonstrate that our approach outperforms both traditional least squares (LS) methods and single-antenna systems, achieving accuracy comparable to conventional multi-antenna positioning. Furthermore, we analyze the impact of different antenna structures on positioning performance, offering practical guidance for FAS antenna design.

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Wenzhi Liu, Zhisheng Rong, Xiayue Liu, Yufei Jiang, Xu Zhu. 2025-03-02. RSSI Positioning with Fluid Antenna Systems. https://arxiv.org/abs/2503.00980

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