Efficient Beamforming Feedback Information-Based Wi-Fi Sensing by Feature Selection
Published in IEEE Wireless Communications Letters, 2024
Wi-Fi sensing leveraging plain-text beamforming feedback information (BFI) in multiple-input-multipleoutput (MIMO) systems attracts increasing attention. However, due to the implicit relationship between BFI and the channel state information (CSI), quantifying the sensing capability of BFI poses a challenge in building efficient BFI-based sensing algorithms. In this letter, we first derive a mathematical model of BFI, characterizing its relationship with CSI explicitly, and then develop a closed-form expression of BFI for 2×2 MIMO systems. To enhance the efficiency of BFI-based sensing by selecting only the most informative features, we quantify the sensing capacity of BFI using the Cramer-Rao bound (CRB) and then propose an efficient CRB-based BFI feature selection algorithm. Simulation results verify that BFI and CSI exhibit comparable sensing capabilities and that the proposed algorithm halves the number of features, reducing 20% more parameters than baseline methods, at the cost of only slightly increasing positioning errors.
Recommended citation: @article{li2024efficient, title={{Efficient Beamforming Feedback Information-Based Wi-Fi Sensing by Feature Selection}}, author={Li, Xin and Hu, Jingzhi and Luo, Jun}, journal={IEEE Wireless Communications Letters}, year={2024}, publisher={IEEE} }
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