Summary
International Workshop on Smart Info-Media Systems in Asia
2021
Session Number:RS3
Session:
Number:RS3-4
Wireless LAN Sensing with Channel State Information Eigenvalue Analysis
Kosuke Tsuji, Ryotaro Isshiki, Yuhei Nagao, Leonardo Lanante, Hiroshi Ochi,
pp.138-143
Publication Date:2021/9/20
Online ISSN:2188-5079
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Summary:
In recent years, research on CSI (Channel State Information) based wireless sensing using wireless LAN has been gathering attention. CSI sensing is a technology that can be applied to human detection and location estimation by observing channel variations in the surrounding physical environment. In this paper, we analyze the CSI in each surrounding environments using beacon frames that are constantly transmitted from wireless LAN access points. We then focus on the time correlation matrix and its eigenvalues obtained from the CSI in order to characterize both the static (e.g. non human obstacles) and dynamic (e.g. human movements) features of the physical environment. In order to obtain accurate temporal correlation matrices, it is necessary to eliminate the effect of phase shift caused by the finite frame synchronization accuracy during reception. In this paper, we introduce a method to remove the effect of phase shift by taking the product of complex conjugates between two receiving antennas, and show the effect of this method.