Region-of-Interest Signaling Vehicular System using Optical Camera Communications

This technical paper introduces an optical camera communication system for vehicles. The purpose of the communication system incorporated into car (using existing light-emitting diode (LED) lights and ordinary cameras) is to add region-of-interest signaling functionality for cars via either their headlights or taillights. A low-data-rate but reliable link via the optical channel is the objective. In particular, the communication system, contributes a spatial modulation approach called spatial-2-phase-shift keying (S2-PSK) that uses a pair of optical light sources on a car (either a pair of rear-LEDs or a pair of front-LEDs) as a transmitter. A typical camera (i.e., less than 30 frames/s), either a global shutter or a rolling shutter, can be used to receive light-modulated data. As a remarkable physical layer (PHY) operating mode among image sensor communication PHY modes recently contributed to IEEE 802.15.7r1 (TG7r1), the communication system, along with technical details on the S2-PSK communication protocol, is described in this paper. In addition, in order to deal with the noisy optical channel and the low-performance challenge of a camera receiver, we have suggested a rate-1/2 line coding and an intelligent decoding approach in our intended vehicular communication scenario. Finally, numerical analyses on the performance of our system and experiment results are addressed.