This whitepaper details phase sanitization algorithms that remove carrier frequency offset, sampling frequency offset, and packet detection delay from multipath-affected CSI measurements captured on commodity Wi-Fi hardware.
Defines the multipath channel model, decomposes the observed CSI phase into true channel phase and hardware-induced errors (CFO, SFO, packet detection delay), and derives the Cramer-Rao bound for phase estimation accuracy.
Presents the linear-fitting sanitization pipeline, benchmarks it against Intel 5300 and Atheros CSI Tool datasets, and shows recovered phase stability sufficient for sub-centimeter ranging and Doppler-based gesture recognition.