OFDM communication signal physical layer encryption method and device

Abstract

The invention belongs to the technical field of communication security, and particularly relates to an OFDM communication signal physical layer encryption method and device, and the method comprises the steps: carrying out the symbol-by-symbol switching of a chaotic phase sequence initial value through a communication signal transmitting end secret key generation module; generating a dynamic composite chaotic sequence by combining the improved Logistic chaotic mapping and the Chebyshev chaotic mapping, and performing nonlinear disturbance on the composite chaotic sequence to obtain a chaotic sequence for encryption; and mapping the chaotic sequence to an OFDM rotation phase vector to complete physical layer encryption. According to the invention, symbol-by-symbol switching of chaotic sequence initial values is carried out; then, generating a composite chaotic sequence by combining the improved Logistic chaotic mapping and the Chebyshev chaotic mapping; the sequence randomness is improved through nonlinear disturbance, the initial value sensitivity of chaotic mapping is fully utilized, the decoding difficulty is further increased, compared with a traditional chaotic phase encryptionscheme, the operand is greatly reduced, the communication safety performance is greatly enhanced while the encryption chaotic performance is improved, and good application value is achieved.

Description

technical field [0001] The invention belongs to the technical field of communication security, in particular to a physical layer encryption method and device for OFDM communication signals. Background technique [0002] For a long time, wireless communication systems have faced threats of attacks from illegal receivers due to their openness and broadcasting nature. Therefore, communication security technology has always been a research hotspot in the field of communication research and development. With the role of communication technology in social life becoming more and more prominent, technological innovation in the field of communication security has become an important measure of the new round of international competition. In some communication scenarios involving national security, military information, diplomatic and commercial secrets, the security performance of communication is even more important than the transmission performance. The security mechanisms of tradi...

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Problems solved by technology

Make full use of the randomness and reciprocity of the phase response of the wireless channel, but it is easily interfered by phase noise, which will lead to the deterioration of the bit error performance of the receiving end

In addition, the transmission efficiency of the three-dimensional constellation modulation used is reduced by 1 / 3 compared with the conventional constellation modulation

The current OFDM physical layer encryption schemes are mainly divided into two categories: one is to use the chaotic sequence generated by the sender to complete the amplitude and phase encryption of the constellation diagram. Problems with poor sequence randomness and high implementation complexity

Another type of scheme introduces the idea of ​​symmetric key encryption, and encrypts the amplitude and phase of the constellation diagram through the obtained equivalent channel information. However, the receiving performance of this type of scheme is greatly disturbed by channel noise.

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