Image Overlay Properties of I-PPM and VPPM Schemes for Rolling Shutter Camera-Based Uplink Screen Camera Communication

To increase data rate of screen camera communication (SCC), rolling shutter camera-based SCCs (RS-SCCs) have been studied. Among modulation schemes, inverse pulse position modulation (I-PPM) is the simplest to maintain constant screen luminance. However, image overlay properties of I-PPM have yet to be elucidated. In this study, the properties were clarified for uplink SCC that combined with a small liquid crystal display and a telephoto RS camera. Type of overlay standard image for I-PPMs and variable PPMs (VPPMs) was altered as parameters. Comparison of symbol error rates among I-PPMs and VPPMs demonstrated the most suitable scheme for image overlay RS-SCC.