BICM-ID scheme for clipped DCO-OFDM in visible light communications.

Visible light communication (VLC) is recommended for indoor transmissions in 5G network, whereby DC-biased optical orthogonal frequency division multiplexing (DCO-OFDM) is adopted to eliminate the inter-symbol interference (ISI) but suffers from considerable performance loss induced by clipping distortion. In this paper, bit-interleaved coded modulation with iterative demapping and decoding (BICM-ID) scheme for clipped DCO-OFDM is investigated to enhance the performance of VLC systems. In order to further mitigate the clipping distortions, a novel soft demapping criterion is proposed, and a simplified demapping algorithm is developed to reduce the complexity of the proposed criterion. Simulation results illustrate that the enhanced demapping algorithm achieves a significant performance gain.