Research And Implementation Of Quantum Noise Stream Cipher In High-Speed IM/DDO-OFDM System

Optical fiber communication is the most important means of communication technology to realize high speed,large capacity and long-distance information transmission.Quantum noise stream cipher(QNSC)is a kind of encryption technology based on mathematical complexity and physical complexity.It can be combined with optical orthogonal frequency division multiplexing system,so it has great application value in optical fiber physical layer security communication.In this paper,the security risks,encryption types and quantum noise stream cipher technology of optical fiber physical layer transmission system are investigated and studied,and the research on QAM/QNSC algorithm is emphasized.In order to adapt to high-speed continuous data flow,a new symbol synchronization algorithm based on training sequence is also proposed.At the same time,a real-time high-speed continuous data stream IM/DDO-OFDM system is built by FPGA.In this system,the security transmission performance of QAM/QNSC algorithm and the symbol synchronization performance of high-speed continuous data stream are demonstrated,which has particularly important reference and research value for ensuring the high-speed safe transmission of optical fiber physical layer.The main work contents and innovative achievements of this paper are as follows:(1)Firstly,the basic principle of OFDM system is derived mathematically,and the key technologies are introduced.Then the IM/DDO-OFDM system structure is introduced in detail.Finally,the basic principle of quantum noise stream cipher is described in detail.(2)The algorithm scheme of 16QAM/4096*4096QAM encrypted transmission of 1 Gbit/s is proposed in IM/DDO-OFDM system,and the back-to-back experiments are carried out.The experimental results show that the symbol error rate of eavesdroppers is approximately 99.999177%,and the system has anti-eavesdropping ability.(3)A symbol synchronization algorithm for high-speed continuous data stream based on training sequence is proposed in IM/DDO-OFDM system.The algorithm can control the phase deviation value of the sampled points after synchronization between positive and negative π/32,and the point deviation value of the sampled points between positive and negative 0.5,without performing symbol synchronization operation for each frame of data.Symbolic synchronization is re-performed only if the point offset is greater than 1 point.(4)The real-time IM/DDO-OFDM system was designed and implemented,and the key modules of the sender and receiver were simulated.Finally,the performance indexes of the real-time system were tested.