Research On Physical Layer Encryption Method Based On OFDM System

As an important technology of 4G and 5G,OFDM technology has a certain practical significance for the safe transmission of data.In view of the security risks of the OFDM system,this paper proposes two composite discrete chaotic systems,namely L ogistic-Sine?LS?system and Sine-Logistic-Tent?SLT?system,and two encryptions based on LS system and SLT system Program.One is an encryption scheme based on XOR operation and neural network,and the other is an encryption scheme based on DNA encoding technology.The two encryption schemes encrypt different steps of the OFDM system flow.Combining the XOR operation and the encryption scheme of the neural network,the input binary bit stream is separately subjected to XOR operation,QAM constellation diagram,and serial-to-parallel conversion.The data added to the pilot is scrambled and encrypted.The encryption scheme based on DNA encoding technology only encrypts the input binary bit stream,which includes DNA encoding,arithmetic and decoding operations.In both encryption schemes,the random process is implemented using a chaotic system.Experiments show that the LS system exhibits chaotic characteristics in the interval[0,4],and the SLT system exhibits chaotic characteristics in the interval?1.05,4?.The Lyapunov exponent and Lyapunov exponent spectrum prove that the LS system and the SLT system have chaotic characteristics The NIST test is performed on the chaotic sequences generated by the LS system and the SLT system.In the 15 tests,the P-value of each test is greater than 0.01,indicating that the chaotic sequence is highly random.The relationship between the ratio and the bit error rate is analyzed.When the signal-to-noise ratio reaches 13,the bit error rate is less than10^-6.The key space of both encryption schemes reaches3?10^{10 8},both of which can resist profiteering attacks and have good encryption effects.This paper has 28 figures,12 tables and 71 references.