Motivation System Design Experiments Coodusioo 动京大盛 Ultrasound Signal Phase Extraction 1150 1100 160 g 0 Extreme Point -Fake Extreme Point 600 Time (millisecond) Peak and Valley Estimation o Find the peak and valley Avoid the error-prone step of static vector estimation o Exclude the fake extreme points: o"Fingerlnterval":the magnitude gap of the finger "SpeedInterval":the speed of the finger Future:use modulated signal to locate the absolute distance and exclude other distance dynamic multipath 20a0 Ke Sun,et al Mobisys'18 June 3.2018 Depth Aware Finger Tapping on Virtual Display 10/22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Motivation System Design Experiments Conclusion Ultrasound Signal Phase Extraction Time (millisecond) 0 500 1000 1500 I/Q (normalized) 800 850 900 950 1000 1050 1100 1150 I Q Extreme Point Fake Extreme Point Peak and Valley Estimation Find the peak and valley Avoid the error-prone step of static vector estimation Exclude the fake extreme points: ”FingerInterval”: the magnitude gap of the finger ”SpeedInterval”: the speed of the finger Future: use modulated signal to locate the absolute distance and exclude other distance dynamic multipath Ke Sun, et al. Mobisys’18 June 3, 2018 Depth Aware Finger Tapping on Virtual Display 10 / 22