A novel timing synchronization method for OFDM based VLC systems

Abstract With an aim to render high data rates and to overcome spectrum crisis, Visible Light Communication (VLC) is explored in which the transmitted signal is constrained to be unipolar. Timing synchronization is one of the critical issue that deteriorates the performance of VLC systems in real time. In this work, traditional synchronization methods are modified according to a realistic VLC channel for Optical Orthogonal Frequency Division Multiplexing (OOFDM) based systems. Further, a new training symbol is designed and a novel frame synchronization method is proposed to improve the estimation accuracy of timing offset. The new training symbol is designed by employing symmetry on a repetitive symbol pattern in frequency domain. Simulation results proves that the proposed frame detection is giving accurate estimate of the symbol timing compared to conventional methods, in the channel having both Line of Sight (LoS) and Non-Line of Sight (NLoS) components under DC bias with clipping distortion.

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