Physical layer secure communication transmission method of wiretap channel based on polar code

Abstract

The invention discloses a physical layer secure communication transmission method of a secret stealing channel based on polar codes, and belongs to the field of communication. According to the invention, the sending end and the legal receiving end are provided with the confusion and deconfusion structures; a chain type encryption structure is designed for the long polar code, storing the information bit key and the freezing set information of the next frame into a preset position in an S set of the current frame by a sending end, and performing encryption and freezing set replacement between frames except for confusion and coding of each frame. A two-dimensional confusion method is designed for a short polar code, a plurality of continuous frames are divided into a group, intra-frame confusion is firstly carried out on each frame in the group, then inter-frame key position confusion is carried out, then second-time intra-frame confusion is carried out, and then polar coding is carriedout. Data transmission can be carried out on a group of short polar codes in combination with chained encryption of long polar codes. According to the method, the channel security is improved, and therequirement on the degradation degree of the eavesdropper channel when the eavesdropper cannot decode completely is reduced.

Description

technical field [0001] The invention belongs to the technical field of communication, and in particular relates to a secure communication method in a wiretap channel based on a polar code. Background technique [0002] At present, most of the confidential communication systems of wireless communication are based on the assumption of no bit error rate transmission at the physical layer. However, in wireless networks, due to a series of influences such as channel fading and noise, the bit error rate of the physical layer cannot be ignored. The ciphertext is not necessarily consistent with the sender, and the transmission error of the ciphertext can lead to the failure of decryption, so the design of the error correction code at the physical layer is of great significance to the security system of wireless communication. [0003] In addition, because the information of the wireless channel is loaded on the communication carrier and spreads freely in the wireless space, this ope...

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Problems solved by technology

[0010] However, in actual transmission, the sending end and the receiving end may not be able to accurately estimate the channel conditions of the eavesdropping end, and because the channel conditions change with time, even if the overall eavesdropping channel is a degraded channel relative to the main channel, at some point The eavesdropping channel conditions may still be better than the main channel. In addition, in 5G communication, polar codes often use short codes, and the reliability and security of short codes are more difficult to guarantee at the same time. This poses a challenge to the design of secure transmission schemes.

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