Polar code security coding method in non-orthogonal multiple access system

Abstract

The invention relates to a polar code security coding method in a non-orthogonal multiple access system, and belongs to the technical field of physical layer security coding. A base station sends information to legal users through a non-orthogonal multiple access system, every two users form a user pair to occupy the same time-frequency resource, and meanwhile, one eavesdropping user eavesdrops the information of the user pair; according to the method, an artificial noise assistance method is utilized to deteriorate an eavesdropping channel, and power distribution among different users in thenon-orthogonal multiple access system is optimized, so that the safety capacity of the system is maximized; based on the channel difference between a main channel and an eavesdropping channel, a polarization code nesting characteristic is utilized at a sending end, a security information interval is constructed to place security information, polarization code coding is carried out, and safe transmission is realized. According to the method, the power distribution among users is optimized, so that the safe transmission capacity of the polar code is maximized; and the method is also suitable fornon-degenerated eavesdropping channels, and is more widely applied to application scenarios.

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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