Constellation Shaping Chaotic Encryption Scheme With Controllable Statistical Distribution for OFDM-PON

In order to improve the signal transmission performance and physical layer security in orthogonal frequency division multiplexing-based passive optical network (OFDM-PON), we propose a constellation shaping chaotic encryption (CSCEn) scheme with controllable statistical distribution. In this scheme, a q uadrature amplitude modulation (QAM) symbol sequence is divided into several sub-sequences, and a further probabilistic shaping (PS) is performed by constellation region replacement in terms of the corresponding statistical information ( SI ). Then the sequence SI is encoded and encrypted into chaotic signal phases by employing our key distribution algorithm. At the receiver, the SI is extracted first to restore the original signal . To verify the effectiveness of this scheme, we successfully demonstrate an encrypted PS-16-QAM signal transmission over a 25-km standard single mode fiber (SSMF). The results show that the proposed scheme can flexibly improve bit error rate (BER) performance with low deployment complexity and provide sufficient security to resist attacks from illegal optical network units ( ONUs), thus it displays a promising application prospect for future secure PON.