Orthogonal Frequency Division Multiplexing (OFDM) is a multi-carrier modulation scheme used in modern Wi-Fi standards (such as IEEE 802.11ac) that divides a wideband channel into multiple orthogonal subcarriers, each carrying a portion of the transmitted signal. In the context of CSI-based human sensing, OFDM is fundamental because it enables the extraction of per-subcarrier channel state information, providing fine-grained amplitude and phase measurements across the frequency domain that capture how human presence, movement, or crowd density perturbs the wireless channel. Wider OFDM channel configurations, such as 80 MHz bandwidths with their correspondingly larger number of subcarriers, are particularly valuable for sensing tasks as they yield richer CSI feature representations and improved spatial and temporal resolution for detecting subtle environmental changes.
Source Papers
- A CSI Dataset for Wireless Human Sensing on 80 MHz Wi-Fi Channels ↗ — A CSI Dataset for Wireless Human Sensing on 80 MHz Wi-Fi Cha
- A Novel Device-Free Counting Method Based on Channel Status Information ↗ — A Novel Device-Free Counting Method Based on Channel Status
- An Overview on IEEE 802.11bf: WLAN Sensing ↗ — An Overview on IEEE 802.11bf: WLAN Sensing
- CRPF-QC: An Efficient CSI Recurrence Plot-Based Framework for Queue Counting ↗ — CRPF-QC: An Efficient CSI Recurrence Plot-Based Framework fo
- CSI-Based People Counting in WiFi Networks: Leveraging Occupancy Detection ↗ — CSI-Based People Counting in WiFi Networks: Leveraging Occup
- Channel State Information from Pure Communication to Sense and Track Human Motion: A Survey ↗ — Channel State Information from Pure Communication to Sense a
- Device-Free Passive Identity Identification via WiFi Signals ↗ — Device-Free Passive Identity Identification via WiFi Signals
- Enabling ISAC on Low-Cost Devices via Spatial-Channel Estimation With a Single-RF Chain ↗ — Enabling ISAC on Low-Cost Devices via Spatial-Channel Estima
- 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
- Human Activity Recognition via Wi-Fi and Inertial Sensors With Machine Learning ↗ — Human Activity Recognition via Wi-Fi and Inertial Sensors Wi
- Investigation of Environment Dependence in Wi-Fi CSI-Based Crowd Counting Systems ↗ — Investigation of Environment Dependence in Wi-Fi CSI-Based C
- OPERAnet, a multimodal activity recognition dataset acquired from radio frequency and vision-based sensors ↗ — OPERAnet, a multimodal activity recognition dataset acquired
- Passive WiFi Radar for Human Sensing Using a Stand-Alone Access Point ↗ — Passive WiFi Radar for Human Sensing Using a Stand-Alone Acc
- Predictable 802.11 packet delivery from wireless channel measurements ↗ — Predictable 802.11 packet delivery from wireless channel mea
- Understanding and Modeling of WiFi Signal Based Human Activity Recognition ↗ — Understanding and Modeling of WiFi Signal Based Human Activi