基于双重混沌加密的OFDM系统设计与实现

Design and Implementation of OFDM System Based on Double Chaotic Encryption

正交频分复用(OFDM)技术被广泛应用于光通信领域,实现信息安全传输具有重要意义。针对OFDM系统中存在的安全隐患,提出一种基于双重混沌加密的OFDM系统,第一次加密通过Tent映射对QAM调制后星座点进行替代,第二次加密利用PWLCM映射生成置乱矩阵对星座图进行置乱,以混淆原始信号,达到更高的安全性,从而保护原始信息。与单重混沌加密相比,双重混沌加密系统具有更大的密钥空间。理论分析和仿真结果表明该系统能在不影响通信传输性能的前提下,提高系统的安全性,保护数据安全。

Orthogonal Frequency Division Multiplexing(OFDM) technology is widely used in optical communication, and realizing secure information transmissions has great significance. Aiming at the potential security risks in OFDM system, in this paper an OFDM system based on the double chaotic encryption is proposed. In the first encryption step, a chaotic sequence generated by the Tent mapping replaces the constellation points after the QAM modulation. In the second encryption step, the Piece Wise Linear Chaotic Mapping(PWLCM) is utilized to generate a scrambling matrix to scramble the constellation to confuse the original signal and achieve a higher security, finally protecting the original information. Compared with the single chaotic encryption, the double chaotic encryption system has a larger key space. Theoretical analysis and simulation results indicate that the proposed system could improve the system security and protect the data security without degrading the communication performance.