A Polar Code Secure Encoding Method in Non-orthogonal Multiple Access System

Abstract

The invention relates to a polar code security encoding method in a non-orthogonal multiple access system, and belongs to the technical field of physical layer security encoding. The base station sends information to legal users through the non-orthogonal multiple access system. Every two users form a user pair to occupy the same time-frequency resources, and there is an eavesdropping user who eavesdrops on the information of the user pair; using the artificial noise auxiliary method, the deterioration Eavesdropping on the channel, while optimizing the power allocation between different users in the non-orthogonal multiple access system, so as to maximize the security capacity of the system; based on the channel difference between the main channel and the eavesdropping channel, the polar code is used at the sending end The nesting feature constructs a security information section to place security information and encode it with polar codes to achieve secure transmission. The method optimizes the power allocation among users to maximize the secure transmission capacity of the polar code; it is also applicable to non-degenerate eavesdropping channels, and the application scenarios are more widely applicable.

Description

technical field [0001] The invention relates to a polar code security encoding method in a non-orthogonal multiple access system, and belongs to the technical field of physical layer security encoding. Background technique [0002] In the 1970s, Wyner constructed a "tapping channel" model based on information theory, and analyzed the possibility of establishing an almost completely secure communication link without relying on exchanging keys. In Wyner's "eavesdropping channel" model, when the eavesdropping channel is a degenerated channel of the main channel, the channel capacity of the eavesdropper Eve is smaller than the channel capacity of the main channel, then there is a security greater than zero between the sender Alice and the information receiver Bob Capacity; at this time, there is a certain encoding method, so that the legitimate communicator Alice and Bob can communicate reliably, so that the amount of information obtained by the eavesdropper Eve is zero. [000...

AI Technical Summary

Problems solved by technology

[0004] Although the existing secure transmission schemes based on polar codes can obtain security capacity, the existing schemes need to assume that the wiretapping channel is the degenerated channel of the main channel. The channel does not satisfy the degenerate relation

In addition, the security transmission rate in the actual scene is small, and there is a lack of scheme design on how to optimize the security capacity

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