Non-Line-of-Sight Optical Camera Communication in a Heterogeneous Reflective Background

Abstract

In the last few years, optical camera communication (OCC) has benefited from built-in CMOS image sensors in smart devices. OCC is now considered a candidate for incorporation into IEEE 802.15.7r1. A major study on OCC was conducted for line-of-sight (LOS) environments. To enable users to receive OCC signals reflected from any surface easily, we considered non-LOS (NLOS) OCC in a heterogeneous reflective background in this study. A modified background subtraction method was proposed to identify the transmitted modulated signal that was recorded in an image. Then, the majority vote principle was used to restore the damaged pixels that were primarily caused by nonuniform reflection from the heterogeneous reflective background. The experimental results obtained after using a self-built NLOS OCC system demonstrated a significant improvement in the bit error rate when the proposed OCC signal recovery method was used for different distances between a smartphone and a heterogeneous reflective background.