Radio-based Device-free Activity Recognition with Radio Frequency Interference

Bo Wei, We Hu, Mingru Yang, Chun Tun Chou

    Research output: Chapter in Book/Report/Conference proceedingConference contribution


    Activity recognition is an important component of many pervasive computing applications. Device-free activity recognition has the advantage that it does not have the privacy concern of using cameras and the subjects do not have to carry a device on them. Recently, it has been shown that channel state information (CSI) can be used for activity recognition in a device-free setting. With the proliferation of wireless devices, it is important to understand how radio frequency interference (RFI) can impact on pervasive computing applications. In this paper, we investigate the impact of RFI on device-free CSI-based location-oriented activity recognition. We conduct experiments in environments without and with RFI. We present data to show that RFI can have a significant impact on the CSI vectors. In the absence of RFI, different activities give rise to different CSI vectors that can be differentiated visually. However, in the presence of RFI, the CSI vectors become much noisier and activity recognition also becomes harder. Our extensive experiments shows that the performance of state-of-the-art classification methods may degrade significantly with RFI. We then propose a number of counter measures to mitigate the impact of RFI and improve the location-oriented activity recognition performance. Our evaluation shows the proposed method can improve up to 10% true detection rate in the presence of RFI. We also study the impact of bandwidth on activity recognition performance. We show that with a channel bandwidth of 20 MHz (which is used by WiFi), it is possible to achieve a good activity recognition accuracy when RFI is present.
    Original languageEnglish
    Title of host publicationIPSN '15 Proceedings of the 14th International Conference on Information Processing in Sensor Networks
    ISBN (Electronic)978-1-4503-3475-4
    Publication statusPublished - 13 Apr 2015
    Event14th ACM/IEEE Conference on Information Processing in Sensor Networks - Seattle, United States
    Duration: 13 Apr 201516 Apr 2015


    Conference14th ACM/IEEE Conference on Information Processing in Sensor Networks
    Abbreviated titleIPSN 2015
    Country/TerritoryUnited States
    Internet address


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