A hybrid OFDM-WDM visible light communications

The paper presents a hybrid orthogonal frequency division multiplexing (OFDM) - wavelength division multiplexing (WDM) visible light communication (VLC). Direct detection is adopted in place of complex digital signal processing such as channel estimation and channel equalization, or even forward error corrections. Generic red, green and blue light emitting diodes (LED) are used for high-speed WDM based 3-channel VLC and white LED for indoor illumination. In each channel, we have used direct current optical OFDM to improve the frequency utilization efficiency. We report an experimental data rate of 288 Mb/s over a transmission span of 1m for indoor applications.