A multispectral mixed white light WDM-VLC system combining color domain with time domain

Since rare multi-primary white LED, traditional Wavelength Division Multiplexing (WDM) visible light communication (VLC) system only has R, G, B three channels. In view of the WDM technology restricted by white LED device in VLC, a method of multispectral mixed light optical communication is proposed. According to the color characteristic of LED light, feature of multi-pulse position modulation (MPPM) and the approach of mixing light, a MPPM dimming modulation is designed for each channel, which uniforms the color and time domain that can realize communication and white light output in the meantime. A multispectral mixed light optical communication system is built using four single-color LEDs. The experimental results show that a white color, 5500K color temperature, is obtained when four channels parallel communication, and chromatic aberration is indecipherable for human eyes (CIE 1976 Δu'ν'<0.005). Multispectral mixed light optical communication is feasible.