Xuelin Yang, Xiaonan Hu, Zanwei Shen, Hao He, Weisheng Hu, and Chenglin Bai, Chaotic signal scrambling for physical layer security in OFDM-PON (invited), ICTON 2015 - 17th International Conference on Transparent Optical Networks, Budapest, Hungary, July 5 - July 9, 2015, Tu.A1.4, DOI: 10.1109/ICTON.