Optimal symmetric double-sided signal clipping in DCO-OFDM visible light communication

In this paper, the optimal DC bias value of symmetric double-sided signal clipping in DC-biased optical orthogonal frequency division multiplexing (DCO-OFDM) visible light communication (VLC) system is deduced. Double-sided clipping is necessary due to the unipolarity of the optical intensity-modulated, direct-detected (IM/DD) system and power limit of the transmitter. Symmetric double-sided clipping is adopted to achieve wider dynamic range. Clipping noise is analyzed for system performance investigation. The optimal DC bias value is deduced by minimizing the system bit error ratio (BER) at given transmitter optical power. An equation of signal to noise ratio (SNR), signal energy, and optimal DC bias value is derived. Finally, the optimal algorithm is verified through a BER simulation at different DC bias values.