Low-complexity blind timing synchronization for ACO-OFDM-based optical wireless communications

In this paper, we present a novel technique for coarse timing synchronization for Asymmetrically-Clipped Optical Orthogonal Frequency Division Multiplexing (ACO-OFDM) systems. This technique is tailored specifically for the ACO-OFDM waveform, and performs coarse symbol timing synchronization without the need for training data. By using a specific symmetry property of the ACO-OFDM time-domain signal, the method can achieve accurate symbol timing synchronization with very low implementation complexity. Simulation results confirm this, and also show that the cyclic prefix-based correlation methods used commonly in traditional OFDM systems, such as 802.11×, cannot be applied to ACO-OFDM systems. The proposed method, therefore, provides an ideal replacement for the cyclic prefix-based method for future systems employing ACO-OFDM.