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.

[1]  Masao Nakagawa,et al.  Fundamental analysis for visible-light communication system using LED lights , 2004, IEEE Transactions on Consumer Electronics.

[2]  Ke Xizheng,et al.  An Optimal Lights Layout Scheme for Visible-Light Communication System , 2007, 2007 8th International Conference on Electronic Measurement and Instruments.

[3]  Rafael Perez-Jimenez,et al.  OFDM over indoor wireless optical channel , 2005 .

[4]  V. Jungnickel,et al.  Adaptive Optical Wireless OFDM System with Controlled Asymmetric Clipping , 2007, 2007 Conference Record of the Forty-First Asilomar Conference on Signals, Systems and Computers.

[5]  Jean Armstrong,et al.  Comparison of Asymmetrically Clipped Optical OFDM and DC-Biased Optical OFDM in AWGN , 2008, IEEE Communications Letters.

[6]  H. Haas,et al.  On the Performance of Different OFDM Based Optical Wireless Communication Systems , 2011, IEEE/OSA Journal of Optical Communications and Networking.

[7]  Harald Haas,et al.  Indoor broadcasting via white LEDs and OFDM , 2009, IEEE Transactions on Consumer Electronics.

[8]  Rafael Perez-Jimenez,et al.  Adaptive OFDM system for communications over the indoor wireless optical channel , 2006 .

[9]  Z. Ghassemlooy,et al.  Orthogonal frequency division multiplexing for indoor optical wireless communications using visible light LEDs , 2008, 2008 6th International Symposium on Communication Systems, Networks and Digital Signal Processing.

[10]  Xia Chen,et al.  A Low Complexity Pilot-Aided Channel Estimation Resisting Residual Timing Errors for OFDM Systems , 2007, 2007 IEEE 18th International Symposium on Personal, Indoor and Mobile Radio Communications.

[11]  John R. Barry,et al.  Indoor Channel Characteristics for Visible Light Communications , 2011, IEEE Commun. Lett..