Evaluation of clipping effect on OFDM signals for visible light communications

In this paper, we evaluate Orthogonal Frequency Division Multiplexing (OFDM) systems with clipping method for Visible Light Communications (VLCs). Clipping can efficiently reduce Peak-to-Average Power Ratio (PAPR), improve Signal-to-Noise power Ratio (SNR) by compensating the reduced transmit power, and prevent the necessity of estimating the bias value added at the transmitter to keep the signal real-positive. Besides, since usually VLC has no specific spectrum mask, the out-of-band components generated by clipping can be remained. Thus, there is no need to care peak regrowth which is a typical problem of Clipping And Filtering method (CAF). We show the proposed system can keep the bias constant and improve required SNR for Quadrature Phase Shift Keying (QPSK) modulation by 3 dB compared to the conventional method.