MIMO (Multiple-Input Multiple-Output) sensing refers to the use of multiple transmit and receive antenna pairs in Wi-Fi systems to collect CSI measurements simultaneously across several spatial streams, effectively multiplying the number of available signal observations for a given channel. This spatial diversity is significant for the sensing field because it enriches the CSI data with additional propagation paths and angular information, improving the ability to detect, localize, and classify human activities or environmental changes with greater robustness and resolution. Key variants include single-user MIMO (SU-MIMO), where one device exploits multiple antennas, and multi-user MIMO (MU-MIMO), introduced prominently in Wi-Fi 6 (IEEE 802.11ax), where concurrent transmissions to multiple clients further expand the spatial sensing coverage but also introduce new challenges around isolating sensing-relevant signal components from the aggregated channel responses.
Source Papers
- A survey on CSI-based Wi-Fi sensing datasets and models with a focus on reproducibility ↗ — A survey on CSI-based Wi-Fi sensing datasets and models with
- Exposing the CSI: A Systematic Investigation of CSI-based Wi-Fi Sensing Capabilities and Limitations ↗ — Exposing the CSI: A Systematic Investigation of CSI-based Wi
- Guiding Wi-Fi Sensor Placement for Enhanced CSI-Based Sensing in Stationary Crowd Counting ↗ — Guiding Wi-Fi Sensor Placement for Enhanced CSI-Based Sensin