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


  • 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






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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