Design and experimental demonstration of a real-time 95kbps optical camera communication system

A real-time optical camera communication (OCC) system was designed and implemented. The system jointly utilizes 4 intensity levels for each color and 3 colors of each RGB LED of a 16×16 LED array, resulting in a 64-ary color-intensity modulation (CIM) carrying on 6-bit coded information in each symbol. The LED array is refreshed at 82.5 Hz, and a FPGA controlled commercial CMOS image sensor from a mobile phone operates at a frame rate of 330 fps whose outputs are fed into a PC for real-time signal demodulation. Excluding 60 boarder LEDs and 4 spatial synchronization LEDs, the remaining 192 data-carrying LEDs are able to transmit data at an effective rate of about 95 kbps. Bit error rate below 10~3 over a communication distance up to 1.2 m is achieved without any external optical lens.