Transmission of 16-QAM OFDM Signal with Secure Strategy Technique in DD-OOFDM Systems

The physical layer of optical access network is vulnerable to various attacks. As the dramatic increase of users and network capacity, the issue of physical-layer security becomes more and more important. This paper proposes a physical-enhanced secure strategy for DD-OOFDM system by employing frequency domain chaos scrambling. The FEC coding can also improve the system performance and will not influence the encrypt process. A 2.5Gb/s 16QAM LDPC-OFDM data with Logistic mapped chaos scrambling are successfully transmitted over 40km SSMF. The results show that security sequences protect the system from attacker and keep a good performance for legal receiver.