A 24 Mbit/s Red LED-based Visible Light Communication System Employing DCO-OFDM Modulation

In this paper, we present a 24 Mbit/s visible light communication (VLC) system based on red light emitting diode (LED). For VLC systems, intensity modulation with direct detection (IM/DD) is widely used, which means that the transmitted signal must be nonnegative and real-valued. In this system, we implemented the DCbiased optical orthogonal frequency division multiplexing (DCOOFDM) architecture and solved the synchronization problem in OFDM systems. In addition, the least square (LS) algorithm is used to estimate channel response. We add partial transmit sequence (PTS) and clipping method to reduce the problem of high peak-to-average power ratio (PAPR) in OFDM system. Bit error rates (BER) is zero under 15 cm free space transmission.