Interpixel Interference Mitigation in Visible Light Communication Using Image Sensor

To improve the data rate in a camera-based visible light communication system, multiple LEDs in an LED array are used to transmit multiple bits in one frame. The problem is that LEDs are always captured in the image with some degree of blooming effect. This effect increases the intensity of pixels surrounding the origin LEDs in the image. When multiple LEDs are used, the blooming effect from all LEDs causes the interpixel interference (IPI) problem that greatly degrades the quality of the received signal. This paper analyzes the blooming effect and finds that the IPI problem increases when the number of ``ON”LEDs in the array increases. Through the analysis, this paper proposes a differential coding to minimize the number of ``ON”LEDs in every transmitted frame and thus minimize the IPI effect. The proposed scheme is then verified through simulations. The results show that a lower bit error rate, which indicates a better signal quality, can be achieved by applying the proposed scheme.