The Future of Beyond 5G Sensing: Transforming Activity Recognition with Reconfigurable Intelligent Surfaces

The advent of Beyond 5G (B5G) and the anticipated arrival of 6G have spurred a remarkable impact on various aspects of human life. Next-generation Human Activity Recognition (HAR) systems are poised to advance healthcare, create smart environments, and enhance overall well-being. The imperative for next-gen HAR systems lies in their capability to be intelligent, privacy-preserving, and deeply accurate. These systems, leveraging the cutting-edge capabilities of B5G and 6G, such as Re-configurable Intelligent Surface (RIS), aim to revolutionize the monitoring process and intelligently discern various human activities. Hence, this paper introduces BSgActiv, a smart RIS-enhanced HAR system. BSgActiv utilizes fractional wavelet transform to effectively highlight time and frequency features of activities from the measured channel state information (CSI) reflected from RIS. Afterward, these features are utilized to train a recurrent neural network that records the temporal characteristics of the input, hence promoting activity recognition. Moreover, BSgActiv integrates diverse modules that enhance the deep model's overall observation and ability to withstand and perform well in the presence of noise. BSgActiv evaluations contain two different realistic scenarios, including both non-line-of-sight and multi-floor setups, proofing its efficacy. Particularly, BSgActiv overcomes benchmark techniques and delivers an activity recognition accuracy of 89.7%.