Physical Layer Encryption Scheme Based on Population Evolution Iteration and Nonlinear Companding in CO-OFDM System

A physical layer encryption scheme based on population evolution iteration (PEI) and nonlinear companding is proposed to improve the security and reduce peak-to-average power ratio of the coherent optical orthogonal frequency division multiplexing (CO-OFDM) system. Simulation conducted in a 28Gbaud 16QAM system proves that the scheme can reduce the PAPR by 4dB, while the bit error rate of eavesdropper is about 0.5, which indicates that the scheme can guarantee the security on the premise of ensuring efficient transmission.