Gesture Sensing Using Retransmitted Wireless Communication Signals Based on Doppler Radar Technology

This paper presents a Doppler radar based on an injection-locked quadrature receiver (ILQR) architecture that can use the wireless communication signals from an input cable or an antenna to perform gesture sensing at a short distance. Since the proposed radar does not require an illumination source, radio interference does not occur. To study parametrically the effect of the signal parameters on radar detection performance, a simulation was carried out by modeling the radar system in the discrete-time domain, and the results were verified experimentally using an actuator. In demonstrated applications, the radar uses an input 20 MHz Long-Term Evolution (LTE) signal or captures an ambient Wi-Fi signal to detect several gestures quite successfully.