Experimental investigation of 16.6 Gbps SDM-WDM visible light communication based on a neural network receiver and tricolor mini-LEDs.

Visible light communication (VLC) based on a light-emitting diode (LED) suffers from a limited bandwidth of commercial LED, device nonlinearity, channel distortion, and transmitted power caused by a complex free-space channel, power amplifier, and illuminant devices resulting in a limited data rate. In this Letter, to provide an alternative high-speed solution, we first designed and fabricated three 175 µm tricolor mini-LEDs with various wavelengths. They are used to set up a spatial division multiplexing-wavelength division multiplexing VLC system over a 2 m link. Then we utilize a neural network receiver to replace the traditional channel estimation, equalization, and demodulation at the offline digital signal processing of the receiver. The experiment showed that the data rates of 2.65, 7, and 7 Gbps were achieved in three respective links using quadrature phase shift keying-optical orthogonal frequency division multiplexing. The three data rates have bit-error rates below the forward error correction limit, whose data rate sum of 16.6 Gbps is the highest mini/micro-LED-based VLC, to the best of our knowledge.