Adaptive window thresholding for noise-robust photo detection in OCC

In an image sensor-based visible-light communication, noise reduction is essential for improving the transmission performance because each frame contains received data with various types of noises. In this study, we demonstrate the structures of receive (Rx) and transmit (Tx) frames for optical camera communication (OCC) by using the rolling shutter effect of a complementary metal-oxide semiconductor (CMOS) image sensor. We propose and demonstrate a three-step noise-reduction process for each frame. The additive white Gaussian noise is reduced by using “signal averaging,” and the background noise is reduced via “adaptive window thresholding” with “normalization.” By using the proposed method, this system shows noise tolerance. We experimentally demonstrate an 8.55-kBd error-free optical camera transmission.