R-OFDM Transmission Scheme for Visible Light Communication using RGBA-LED

White light-emitting diode (LED) consisting of red, green, blue, and amber chips (RGBA-LED) has recently been adopted as transmitter in visible light communication (VLC) systems. This paper proposed a reshaped orthogonal frequency division multiplexing (R-OFDM) scheme for RGBA-LED-based VLC systems. In the R-OFDM, the signal is adjusted by separation and biasing after clipping (BAC) operations for transmitting in RGBA-LED. Then, the biasing factor of BAC is derived according to the color mix ratio (CMR) of RGBA-LED. At the receiver, We develop a direct detection algorithm to recover the original data, and analyze its the theoretical bit error rate (BER). Furthermore, a lower bound of the BER is analyzed under high clipping ratio (CR) by using SNR upper bound. Finally, simulation results confirm our theoretical analysis and verify that R-OFDM outperforms the ACO-OFDM in term of BER.