SGRS: A sequential gesture recognition system using COTS RFID

Gesture recognition is an innovative technology which is fundamentally reshaping the way people live, entertain and work. However, most gesture recognition systems focus on the recognition of simple gestures and ignore the full potential of sequential gestures involving a series of temporally-related simple actions in order. This paper presents SGRS, a battery-free, scalable and non-specific sequential gesture recognition system based on COTS RFID. The key insight is that finegrained phase information extracted from RF signals is capable of perceiving various gestures. In SGRS, we meticulously devise gesture recognition mechanism by incorporating the k-means based vector quantizer and string matching algorithm to enable precise and real-time sequential gesture identification. Moreover, an improved edit distance algorithm is proposed for suppressing individual diversity. We implement SGRS and comprehensively evaluate the performance by recognizing traffic command gestures of Chinese traffic police. Experimental result shows that SGRS achieves an average recognition accuracy of 96.2% with eight sequential gestures and is highly robust to both individual diversity and multipath effect.