In order to effectively solve the problem of data transmission security and peak-to-average ratio (PAPR) in an orthogonal frequency division multiplexing passive optical network (OFDM-PON) transmission system, in this paper, a joint encryption scheme of discrete cosine transform (DCT) and selective mapping (SLM) based on chaotic mapping is proposed. In this scheme, the chaotic sequence of a 3D Lorenz chaotic system is used as the row and column index of the DCT matrix and the phase factor of SLM to resist selective plaintext attack, and the system encryption is realized while reducing PAPR. The theoretical analysis and numerical simulation show that the common OFDM-PON, the proposed algorithm, can obtain a PAPR suppression gain of ∼4.8 dB and improve the receiver sensitivity by ∼4 dB . In addition, it shows that, with the increase of row/column index mismatch of the DCT matrix, the bit error rate of the system increases gradually. An encrypted data transmission of 8 GB/s 16-QAM optical OFDM signals is successfully simulated over a 20 km standard single-mode fiber, which proves the excellent confidentiality of the proposed secure transmission.

中文翻译：

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OFDM-PON系统中基于混沌DCT矩阵和SLM算法的联合加密方案

为了有效解决正交频分复用无源光网络（OFDM-PON）传输系统中数据传输的安全性和峰均比（PAPR）问题，本文提出了一种离散余弦变换的联合加密方案。提出了一种基于混沌映射的DCT（DCT）和选择性映射（SLM）。在该方案中，将3D Lorenz混沌系统的混沌序列用作DCT矩阵的行和列索引以及SLM的相位因子，以抵抗选择性明文攻击，并在降低PAPR的同时实现了系统加密。理论分析和数值模拟表明，所提出的通用OFDM-PON算法可获得约4.8 dB的PAPR抑制增益，并将接收器灵敏度提高了约4 dB 。另外，随着DCT矩阵行/列索引失配的增加，系统的误码率逐渐增加。在20 km标准单模光纤上成功地模拟了8 GB / s的16-QAM OFDM信号的加密数据传输，证明了所提出的安全传输的出色机密性。