Expectation-maximization-based channel estimation algorithm for OFDM visible light communication systems

  • Authors

    • Yaseein Soubhi Hussein Asia Pacific University of Technology & Innovation
    • Mohamad Yusoff Alias Multimedia University
    • Ayad A. Abdulkafi Tikrit University
    • Nazaruddin Omar TM Research & Development Sdn Bhd
    • Mohd Kamarulzamin Bin Salleh TM Research & Development Sdn Bhd
    2018-09-24
    https://doi.org/10.14419/ijet.v7i4.15994
  • Bit Error Rate, Channel Estimation, Expectation Maximization, Optical OFDM Visible Light Communication.

  • The tremendous growth of indoor communication requires increased capacity and appropriate quality of services. Visible light communica-tion (VLC) is a green technology that shows great promise in terms of its ability to meet the demand for communication services. Orthogo-nal frequency division multiplexing (OFDM) enables VLC to provide a higher data rate and to combat inter-symbol interference. However, an accurate and efficient channel estimation method is needed for coherent demodulation at the receiver end of an OFDM system. In this paper, a new algorithm for OFDM-based VLC systems is proposed. The algorithm is based on expectation maximization and is called the expectation maximization for visible light communication (EM-VLC) algorithm. The algorithm is implemented to find the maximum-likelihood (ML) estimation of the channel impulse response and to find unknown parameters. In addition, a low-rank minimum mean square error (lr-MMSE) estimator algorithm is developed and its performance is compared with least squares (LS) and minimum mean square error (MMSE) estimators. The proposed EM-VLC algorithm improves the performance of OFDM VLC systems by significantly reducing the bit error rate (BER) and consequently increasing system throughput. The simulation results demonstrate that the EM-VLC algorithm outper-forms the three channel estimation algorithms, LS, MMSE and lr-MMSE.

     

     

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    Soubhi Hussein, Y., Yusoff Alias, M., A. Abdulkafi, A., Omar, N., & Kamarulzamin Bin Salleh, M. (2018). Expectation-maximization-based channel estimation algorithm for OFDM visible light communication systems. International Journal of Engineering & Technology, 7(4), 2638-2645. https://doi.org/10.14419/ijet.v7i4.15994