Demonstration of a sub-pixel outdoor optical camera communication link

Abstract

Optical Camera Communication (OCC) is an Optical Wireless Communication (OWC) technology that relies on general-purpose cameras to perform not only image-related tasks but also to receive data from optical sources. In general terms, OCC has been extensively studied in indoor scenarios and can be a competent and cost-effective alternative solution for wireless data transmission in Smart Cities for medium to long links up to hundreds of meters. In this paper, the feasibility of establishing an outdoor sub-pixel communication link is demonstrated. In this experiment, single 5 mm white LED transmitters located at distances of 90 and 130 m send simultaneous optical codes to a receiver based on a commercial camera, achieving a signal-to-noise ratio of 20 dB and 13 dB, respectively. This work shows that although the geometrical projection within the transmitter's image is less than the pixel area, it is still possible to establish an effective communication link, with 8 bps per transmitter. At 130 m, the best performance was an error rate of 7.2x10-3, and for 90 m, no errors were detected.