Modeling of Multipath Channel and Performance Analysis of MIMO-DCO-OFDM System in Visible Light Communications

When a big path difference exists between the multiple transmitter-receiver links, time dispersion is inevitable. A multipath channel model is proposed for Multiple-input multiple-output (MIMO) Visible light communications (VLC). To combat Intersymbol interference (ISI) as well as increase the channel capacity, a combination of MIMO and Direct-currentbiased Optical orthogonal frequency division multiplexing (DCO-OFDM) is studied. The performance analysis of MIMO-DCO-OFDM taking into account the limitation of the forward current of the off-the-shelf LED is derived. The accuracy of the theoretical results is verified by comparison with the Monte Carlo Bit error ratio (BER) simulation results under different DC bias and different clipping levels.