5G Physica Layer Encryption Method Based On Chaos

Chaotic system has the characteristics of noise-like,wide spectrum,sensitive initial values,pulse autocorrelation and non-periodicity,which make them widely used in various fields.And its application in communication and information encryption is two important directions.In recent years,the combination of chaos and wireless communication physical layer modulation methods to obtain anti multipath performance has attracted attention.At the same time,the encryption application of delayed hyperchaotic system with infinite dimensional key space also shows its unique performance.5G communication has become people's daily means of communication,5G is more suitable for the scene of industrial Internet of things,and the dense terminal set and complex channel environment of industrial Internet of things require communication methods to have better security with large capacity and low delay.How to combine chaos with 5G physical layer modulation and encryption to improve the performance and security of industrial Internet of things has important theoretical significance and application value.Orthogonal frequency division multiplexing(OFDMA)technology is an important method of 5G physical layer multiple access.In this paper,we first combine chaotic shaping filter with orthogonal frequency division multiplexing technology,and propose a chaotic spread spectrum communication under multiple access.Secondly,a physical layer encryption scheme based on delayed Chen system is proposed and its performance is analyzed.The specific research work and conclusions are as follows:1)A multiuser OFDM-DCSK scheme based on Chaotic Shaping Filter and Hadamard index is proposed.The communication system allows multi-user access without increasing bandwidth.Each user is assigned C private subcarriers to transmit its reference signal.The row elements of Hadamard matrix generate chaotic reference signal through chaotic shap ing filter,and the information-bearing signals can share Nm subcarriers.The maximum signal-to-noise ratio(SNR)and lower multiple access interference(MAI)can be obtained when the receiver uses the corresponding matched filter to distinguish users.The maximum likelihood estimation method is used to estimate and map the chaotic reference signal,which is combined with the maximum SNR point sampling operation to form a dual noise reduction mechanism.Then the noise effect is greatly reduced,and the BER performance is improved.The BER performance of the proposed scheme will not deteriorate with the increase of the number of users in Gaussian channel.The energy efficiency of the proposed scheme and the analytical solution of BER in Gaussian channel and multipath fading channel are analyzed.The theoretical analysis shows the advantages of the proposed scheme.Finally,the feasibility and superiority of the proposed scheme are verified by comparative simulation and experiment.The new physical layer modulation method creates a good condition for further improving the physical layer security performance.1)Aiming at the security problem of wireless communication in industrial Internet of things,a physical layer information encryption scheme based on delayed Chen system is proposed.The delayed Chen system has the advantages of infinite dimensional phase space,multiple positive Lyapunov exponents and the ability to generate chaotic sequences with high complexity.Combining it with encryption scheme can improve the security performance.This scheme is divided into three parts:the construction of dynamic Hash key function based on chaos,the mark diffusion and the information obfuscation operation based on S-box of delayed Chen system.First,the channel information between the preamble and the legitimate user is transformed as the hash input,and the latter is updated at each session to obtain a dynamic key value with good random characteristics.Secondly,Hash output is used to mark and diffuse plaintext information,which makes the interaction among plaintext,ciphertext and key more complex and effectively resists malicious attacks,such as plaintext selective attack.The S-box constructed by delayed Chen system has obvious advantages in nonlinearity and avalanche characteristics.It can be used to confuse ciphertext to get better encryption effect.The advanced and security of the encryption scheme is verified by simulation analysis.