Using GAN to Enhance the Accuracy of Indoor Human Activity Recognition
This addresses the data collection bottleneck for researchers and practitioners in WiFi-based activity recognition, though it is incremental as it combines existing methods.
The paper tackles the problem of expensive data collection for indoor human activity recognition using WiFi signals by generating synthetic data with a GAN, achieving a 3.4% increase in classification accuracy and a 16% reduction in Log loss.
Indoor human activity recognition (HAR) explores the correlation between human body movements and the reflected WiFi signals to classify different activities. By analyzing WiFi signal patterns, especially the dynamics of channel state information (CSI), different activities can be distinguished. Gathering CSI data is expensive both from the timing and equipment perspective. In this paper, we use synthetic data to reduce the need for real measured CSI. We present a semi-supervised learning method for CSI-based activity recognition systems in which long short-term memory (LSTM) is employed to learn features and recognize seven different actions. We apply principal component analysis (PCA) on CSI amplitude data, while short-time Fourier transform (STFT) extracts the features in the frequency domain. At first, we train the LSTM network with entirely raw CSI data, which takes much more processing time. To this end, we aim to generate data by using 50% of raw data in conjunction with a generative adversarial network (GAN). Our experimental results confirm that this model can increase classification accuracy by 3.4% and reduce the Log loss by almost 16% in the considered scenario.