Privacy-preserving activity recognition method based on WiFi signals: adaptive CSI enhancement and deep reinforcement learning
摘要
This paper aims to propose a WiFi-based human activity recognition method addressing privacy protection, recognition accuracy, and cost. The technique achieves non-contact recognition by extracting human activity features from Channel State Information (CSI). Adaptive Kalman Filtering combined with the Savitzky–Golay filter enhances the CSI data quality and suppresses environmental interference. A variance-based sliding window threshold method is used to segment activity periods accurately. Third-order cumulant features are extracted via high-order spectral analysis, and the Mutual Information Feature Selection (MIFS) algorithm selects robust features to improve environmental adaptability and behaviour discrimination. Finally, a behaviour recognition model is constructed by integrating a Gaussian Mixture Model–Hidden Markov Model (GMM–HMM) with a Deep Q-Network (DQN) to classify segmented activities. Experimental results demonstrate that the proposed method achieves superior accuracy and robustness compared to baseline approaches.