Research On Secure Coding Algorithm Using Polar Code Over Gaussian Wiretap Channel

With the wide application and rapid development of wireless communication technology,malicious eavesdropping can easily happen in the signal coverage area.However,technology research of wireless secure transmission is far behind the rapid development of wireless communication technology.In the process of wireless communication,Personal privacy,business secrets and military sensitive information have been faced with a series of security challenges,such as illegal eavesdropping by the third parties,tampering and interference.In order to prevent private information from being tapped by the third party basically,ensuring the security of information transmission from the physical layer directly is becoming a research hotspot in the industry.Due to the polarization properties of the polarization code itself and a low complexity of encoding and decoding,the polarization code is very suitable for the physical layer security coding.For the above-mentioned reasons,we will make research on the problem of the physical layer security coding based on polarization coding in Gauss eavesdropping channel in this paper.First,This paper explains the basic theory about the physical layer security encoding,analyzes the causes of polarization for code polarization and its properties,derives the principle of polarization coding and decoding,describes coding and decoding process in detail.Second,according to Gauss degraded wiretap channel model,based on the original polarization code security encoding algorithm proposed a dynamic "key" encryption algorithm.The simulation results show that compared with the original security coding algorithm,dynamic "key" encryption algorithm reduces the error rate of receiving legitimate users,improves the security of legal communication.Besides,due to the use of the secure channel and non-security channel,the dynamic "key" encryption algorithm saves channel resources effectively.Finally,according to Gauss degraded Wiretap Channel Model,this paper extends the single feedback structure to multiple feedback structures in the case of non-degraded channel of the main channel and derives the probability density formula for the multiple feedback structures,a multiple feedback model(MFM)for non-degenerate Gauss eavesdroppingchannel is also obtained.The simulation results show that Multiple feedback structures lead to a slight reduction in the reliability of legitimate communication,but the security of legal communication is greatly improved.It can be explained that the multiple feedback model can sacrifice certain communication reliability to improve the security of communication.