CSISensing: Channel State Information for 6G Sensing

CSISensing defines the signal-processing pipeline that turns raw Wi-Fi and 5G-Advanced channel estimates into calibrated CSI streams for radar-grade sensing, powering device-free gesture recognition, intrusion detection, and 6G joint communication-radar systems.

CSISensing Joint Radar-Communication Architecture

ISAC Core: CSI Sensing Engine — IEEE 802.11bf & Subcarrier Phase Extractor

6G ISAC Nodes & Beamforming Subsystems

Phase Sanitization Filter
CFO / SFO Compensator
Spatial Gesture Classifier
Doppler Angle-of-Arrival
Wi-Fi 7 Multi-Link Channel

Architectural Layers & Waveform Pipelines

Layer 1: Sub-THz & RF Phased Array Front-End (GaN/InP PA / True-Time-Delay (TTD) / 140 GHz D-Band Active Arrays): Ultra-wideband signal generation, beam squint mitigation, and simultaneous transmission of communication and radar probing waves.
Layer 2: Dual-Functional Waveform & Baseband DSP (OTFS / Cyclic Prefix OFDM / Ambiguity Function Shaping / 2D-FFT): Orthogonal modulation in delay-Doppler domains, low peak-to-average power ratio coding, and deterministic clutter cancellation.
Layer 3: Joint Signal Processing & Point Cloud Extraction (Range-Doppler Matrix / MUSIC & ESPRIT DOA / CFAR Detection): High-resolution angle of arrival estimation, velocity extraction, ghost artifact elimination, and 4D spatial coordinate synthesis.
Layer 4: Multi-Static Mesh & 6G Sensing-as-a-Service (3GPP Rel-19 SBA / Sensing Function (SF) / NEF APIs / RIS Control): Cooperative radar data fusion across distributed cells, intelligent surface reflection control, and exposure of real-time environmental digital twins.

Sensing Telemetry & Benchmarks: <2.5 cm (Range Resolution) | ±0.05 m/s (Velocity Precision) | 0.1° (Angular Accuracy (DOA)) | 100 Hz (Sensing Update Rate)

From Raw Channel Estimates to Calibrated CSI in CSISensing

Commodity Wi-Fi and 5G-Advanced radios expose per-subcarrier channel estimates that, once sanitized for phase noise and clock offsets, become a high-resolution sensing modality. CSISensing specifies the calibration, feature extraction, and standards alignment needed to turn this CSI data into reliable radar-grade measurements without dedicated radar hardware.

Core Engineering Areas

IEEE 802.11bf Wireless LAN Sensing Standard and Subcarrier CSI Extraction — Specification of the IEEE 802.11bf amendment for Wi-Fi sensing, covering trigger-based sounding, subcarrier-level CSI reporting, and the calibration pipeline required to extract usable range-Doppler information from commodity access points.
Passive Intrusion Detection and Gesture Recognition via Spatial CSI Amplitude/Phase — Device-free sensing techniques that convert CSI amplitude and phase fluctuations into intrusion alerts and gesture classifications, using spatial diversity across multiple receive antennas to localize and characterize human motion.
Eliminating Phase Offsets and Carrier Frequency Offsets in Commodity CSI Hardware — Correction techniques for the phase noise, carrier frequency offset (CFO), and sampling frequency offset (SFO) that corrupt raw CSI measurements from non-coherent commodity radios, restoring the phase stability required for sensing.