Impact of Defocusing of the Camera Lens on the Image in Optical Camera Communications

In this paper, we propose a theoretical model for the intensity of a blurred image of a light source (LS) due to defocusing in optical camera communications. The blurred image is characterized with four parameters of half power full width, maximum intensity, left and right slope of hazy area and we relate them to the LS, channel, and camera settings. We experimentally investigate the impact of these parameters on characterization of the blurred image and compare it with the predicted data. The results show that if the size of the LS compared to its distance from the camera is less than a certain value set by the camera settings, the interference level between two close LSs increases, i.e. by increasing the link span, the size of the image increases.