Description
Beamforming combines signals across multiple TX or RX antennas with calibrated weights so that constructive / destructive interference shapes the spatial sensitivity pattern. Wi-Fi's beamforming feedback (V-matrix in 802.11ac/ax) is itself a sensing observable — in some commodity APs it is more accessible than CSI. Sensing-aware beamforming design is also a core ISAC topic.
When it's used
- Directional sensing of specific zones / individuals
- Beamforming-feedback-based sensing where CSI is locked down
- ISAC waveform design with sensing constraints
Limitations
- Requires known antenna geometry and calibration
- Beam-training overhead in standards-compliant operation
- Vendor-specific beamforming quantisation reduces sensing fidelity