Statistical distribution of the transmitter’s per-frame initial phase φ

Determine the statistical distribution of the transmitter’s per-frame initial phase φ in ESPARGOS’s WiFi CSI acquisition to enable precise modeling of the common phase rotation affecting channel coefficients within each frame.

Background

The authors model received CSI vectors as being affected by an unknown common phase rotation per frame, denoted φ, arising from transmitter oscillator offsets and drift. While they develop a covariance-based approach that circumvents estimating φ directly, the lack of a known distribution for φ limits formal statistical modeling and analysis.

Characterizing the distribution of φ would inform more accurate estimators and potentially improve performance of algorithms that depend on phase behavior across frames, especially in scenarios with varying oscillator characteristics.