Dang, K., P. Nguyen, and H. Ochi. “An Auto Synchronization Technique of Unipolar MPAM Signals in OFDM and Its Application for Optical Wireless Communication Systems”. Science and Technology Development Journal, Vol. 18, no. 3, Aug. 2015, pp. 218-24, doi:https://doi.org/10.32508/stdj.v18i3.839.