A post-processing channel estimation method for DCO-OFDM Visible Light Communication

In this paper, we analyze the channel estimation technique for OFDM (orthogonal frequency division multiplexing) used in VLC (Visible Light Communication system). A Post-Processing DFT (Discrete Fourier Transformation) channel estimation method was proposed to improve the system performance by eliminating the noise outside the maximum channel delay. After linear interpolation, the channel estimation is transformed into time domain by DFT and truncate according to the maximum channel delay, and then goes back to frequency domain. LS (Least Square) algorithm and comb-type pilot is used in the simulation to validate the effectiveness of this DFT-based post-processing channel estimation method, and the BER performance is demonstrated with QPSK, 16-QAM and 64-QAM constellation order, also, different pilot number is considered.