Demonstration of High-Speed 2 × 2 Non-Imaging MIMO Nyquist Single Carrier Visible Light Communication With Frequency Domain Equalization

We experimentally demonstrate a high-speed 2 × 2 non-imaging multiple-input multiple-output nyquist single carrier visible light communication system. Two commercially available blue light emitting diodes with 3 dB electrical bandwidth of 10 MHz and two avalanche photo diodes with 3 dB electrical bandwidth of 100 MHz are used as transmitters and receivers, respectively. A frequency domain equalization method based on two pairs of time-multiplexed training symbols is proposed, which allows de-multiplexing and post-equalization simultaneously processing in one step. Frequency domain averaging and time-domain averaging are also implemented and analyzed in this paper. In this demonstration, the overall data rate is 500 Mb/s. The measured bit error rates for two receivers are both below the 7% pre-forward-error-correction threshold of 3.8 ×10^-3 after 40 cm free-air transmission.