A High-Speed Visible Light Communication System Using Pairs of Micro-Size LEDs

We designed and experimentally demonstrated a spatial diversity visible light communication (VLC) system based on a blue micro-size LED consisting of two parallel pixels. Since the size-dependent effect on the electrical and optical performance of LED, a group of such LEDs with the same structure but different pixel sizes from 75- μ m to 175- μ m diameters are fabricated and packaged to optimize the system. The experimental results showed the trade-off between the modulation depth and bandwidth. Furthermore, the system using a pair of 75- μ m micro-LEDs can reach up to 1.20-Gbps data rate, which is the highest among the packaged LED group, with the bit-error rate (BER) below the forward error correction (FEC) floor of 3.8 ×10
^-3
based on orthogonal frequency division multiplexing (OFDM) and a simple spatial diversity scheme. This work is conducive to the system design based on large-scale micro-LED arrays in the future.