Dimmable optical camera communications with WDM using RGB and infrared LEDs

Abstract

We propose an optical camera communication (OCC) system with dimming control, employing wavelength division multiplexing (WDM) with RGB and infrared (IR) light sources. The system uses pulse width modulation (PWM) for brightness adjustment, with IR transmission integrated into both PWM “ON” and “OFF” slots to compensate for data rate losses caused by dimming. To eliminate interference at the receiver, we implement a scheme that utilizes color correction and principal component analysis to separate the hybrid signal, with an optimization approach to fine-tune the IR intensity. This design achieves a data rate of 10.8 Kb/s at 30 fps under full dimming, offering a 33.3% improvement over RGB-only transmission. At a duty cycle of 0.5, the data rate further improves by 75.6%.