Mothvation System Design Experimonts Coodusic 和京大盛 Ultrasound Signal Phase Extraction Tapping finger t40 I(normi密d o Phase-based distance measurement Measure phase changes caused by the movement 16 single frequencies(17~22 kHz)linear regression Challenge: o Phase changes caused by the finger movements is much smaller. o Multipath interference in finger movements is much more significant. Dao Ke Sun,et al Mobisys'18 June 3.2018 Depth Aware Finger Tapping on Virtual Display 9/22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Motivation System Design Experiments Conclusion Ultrasound Signal Phase Extraction I (normalized) 700 900 1100 1300 1500 1700 Q (normalized) 200 400 600 800 1000 1200 1400 Pushing hand Tapping finger I (normalized) 1000 1050 1100 1150 1200 Q (normalized) 900 950 1000 1050 1100 Tapping finger Tapping finger Phase-based distance measurement Measure phase changes caused by the movement 16 single frequencies (17 ∼ 22 kHz) linear regression Challenge: Phase changes caused by the finger movements is much smaller. Multipath interference in finger movements is much more significant. Ke Sun, et al. Mobisys’18 June 3, 2018 Depth Aware Finger Tapping on Virtual Display 9 / 22