Description

WiFi CSI sensing is the concrete realisation of wifi-sensing that uses Channel State Information (per-subcarrier complex channel response) as its observation, rather than scalar RSSI. It is the core method family of this thesis — every Chapter 4 (CSI sensing) experiment lives inside this category. Pipelines typically convert raw CSI into amplitude / phase / ratio features and feed them to learned models for occupancy, motion, or activity inference.

When it's used

  • All Chapter-4 CSI experiments in the thesis testbed
  • Crowd-counting and density-estimation studies
  • Activity / gesture / gait recognition on commodity APs
  • Baselines compared against future BLE-calibrated CSI methods

Limitations

  • Inherits commodity-NIC constraints (Intel 5300, Atheros, Nexmon, ESP32)
  • Environment dependence is acute — models rarely transfer between rooms
  • Standardisation only emerging via 802.11bf

Source Papers

  • koo2026_a08d — Transformer-based CSI sensing
  • guarino2026_e72c — recent CSI sensing pipeline
  • wu2022_75d3 — CSI-ratio CSI sensing model
  • taehyeon2026_4bd5 — CSI sensing benchmark
  • zhang2022_5822 — CSI sensing under environment shift

30 vault papers use this method

Titles and DOIs only — no abstracts, no analyses.

  • WiFi Sensing with Channel State Information 2020 DOI ↗
  • Device-free occupancy detection and crowd counting in smart buildings with WiFi-enabled IoT 2018 DOI ↗
  • Wi-CaL: WiFi Sensing and Machine Learning Based Device-Free Crowd Counting and Localization 2022 DOI ↗
  • Cross-Domain WiFi Sensing with Channel State Information: A Survey 2023 DOI ↗
  • Channel State Information (CSI) Amplitude Coloring Scheme for Enhancing Accuracy of an Indoor Occupancy Detection System Using Wi-Fi Sensing 2024 DOI ↗
  • WiMANS: A Benchmark Dataset for WiFi-based Multi-user Activity Sensing 2025 DOI ↗
  • WiFi CSI-Based Device-free Multi-room Presence Detection using Conditional Recurrent Network 2021 DOI ↗
  • A CSI Dataset for Wireless Human Sensing on 80 MHz Wi-Fi Channels 2023 DOI ↗
  • Practical Issues and Challenges in CSI-based Integrated Sensing and Communication 2022 DOI ↗
  • On CSI and Passive Wi-Fi Radar for Opportunistic Physical Activity Recognition 2022 DOI ↗
  • Towards Energy Efficient Wireless Sensing by Leveraging Ambient Wi-Fi Traffic 2024 DOI ↗
  • MUSE-Fi: Contactless MUti-person SEnsing Exploiting Near-field Wi-Fi Channel Variation 2023 DOI ↗
  • A Foundational Edge-AI Sensing Framework for Occupancy-Driven Energy Management in SMOs 2026 DOI ↗
  • Human Sensing by Using Radio Frequency Signals: A Survey on Occupancy and Activity Detection 2023 DOI ↗
  • CrossSense: Towards Cross-Site and Large-Scale WiFi Sensing 2018 DOI ↗
  • WiFi CSI-based device-free sensing: from Fresnel zone model to CSI-ratio model 2022 DOI ↗
  • Efficient machine learning for Wi-Fi CSI-based human activity recognition using fast Monte Carlo based feature extraction 2026 DOI ↗
  • Simultaneous Crowd Estimation in Counting and Localization Using WiFi CSI 2021 DOI ↗
  • Simultaneous Crowd Estimation in Counting and Localization Using WiFi CSI 2021 DOI ↗
  • Simultaneous Crowd Estimation in Counting and Localization Using WiFi CSI 2021 DOI ↗
  • OPERAnet, a multimodal activity recognition dataset acquired from radio frequency and vision-based sensors 2022 DOI ↗
  • Exposing the CSI: A Systematic Investigation of CSI-based Wi-Fi Sensing Capabilities and Limitations 2023 DOI ↗
  • Exposing the CSI: A Systematic Investigation of CSI-based Wi-Fi Sensing Capabilities and Limitations 2023 DOI ↗
  • Human Activity Recognition via Wi-Fi and Inertial Sensors With Machine Learning 2024 DOI ↗
  • Device-Free Passive Identity Identification via WiFi Signals 2017 DOI ↗
  • A Survey on Green Wireless Sensing: Energy-Efficient Sensing via WiFi CSI and Lightweight Learning 2026 DOI ↗
  • CSI-Chain: A Complete End-to-End Framework for WiFi CSI Sensing 2026 DOI ↗
  • SDP: A Unified Protocol and Benchmarking Framework for Reproducible Wireless Sensing 2026 DOI ↗
  • NearSense: Exploring NearLink for New-Generation Wireless Sensing 2026 DOI ↗
  • A survey on CSI-based Wi-Fi sensing datasets and models with a focus on reproducibility 2026 DOI ↗