TY - GEN
T1 - Protecting Human Activity Signatures in Compressed IEEE 802.11 CSI Feedback
AU - Seif, Mohamed
AU - Kludze, Atsutse
AU - Ghasempour, Yasaman
AU - Poor, H. Vincent
AU - Calin, Doru
AU - Goldsmith, Andrea J.
N1 - Publisher Copyright:
© 2026 IEEE.
PY - 2026
Y1 - 2026
N2 - Explicit channel state information (CSI) feedback in IEEE 802.11 conveys transmit beamforming directions by reporting quantized Givens rotation and phase angles that parametrize the right-singular subspace of the channel matrix. Because these angles encode fine-grained spatial signatures of the propagation environment, recent work have shown that plaintext CSI feedback can inadvertently reveal user activity, identity, and location to passive eavesdroppers. In this work, we introduce a standards-compatible differentially private (DP) quantization mechanism that replaces deterministic angular quantization with an ϵ-DP stochastic quantizer applied directly to the Givens parameters of the transmit beamforming matrix. The mechanism preserves the 802.11 feedback structure, admits closed-form sensitivity bounds for the angular representation, and enables principled privacy calibration. Numerical simulations demonstrate strong privacy guarantees with minimal degradation in beamforming performance.
AB - Explicit channel state information (CSI) feedback in IEEE 802.11 conveys transmit beamforming directions by reporting quantized Givens rotation and phase angles that parametrize the right-singular subspace of the channel matrix. Because these angles encode fine-grained spatial signatures of the propagation environment, recent work have shown that plaintext CSI feedback can inadvertently reveal user activity, identity, and location to passive eavesdroppers. In this work, we introduce a standards-compatible differentially private (DP) quantization mechanism that replaces deterministic angular quantization with an ϵ-DP stochastic quantizer applied directly to the Givens parameters of the transmit beamforming matrix. The mechanism preserves the 802.11 feedback structure, admits closed-form sensitivity bounds for the angular representation, and enables principled privacy calibration. Numerical simulations demonstrate strong privacy guarantees with minimal degradation in beamforming performance.
KW - CSI Feedback
KW - CSI-Based Sensing Attacks
KW - Differential Privacy
KW - Givens Angle Quantization
KW - IEEE 802.11ac/ax
KW - MIMO Beamforming
UR - https://www.scopus.com/pages/publications/105044253077
U2 - 10.1109/DySPAN69846.2026.11571161
DO - 10.1109/DySPAN69846.2026.11571161
M3 - Conference contribution
AN - SCOPUS:105044253077
T3 - 2026 IEEE International Symposium on Spectrum Innovation, DySPAN 2026
BT - 2026 IEEE International Symposium on Spectrum Innovation, DySPAN 2026
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2026 IEEE International Symposium on Spectrum Innovation, DySPAN 2026
Y2 - 11 May 2026 through 14 May 2026
ER -