6G RIS-assisted physical layer security joint optimization method in NOMA system

Abstract

The invention belongs to the technical field of wireless communication, and discloses a 6G RIS-assisted physical layer security joint optimization method in a NOMA system. The method comprises the steps: in a downlink MISO communication network with one base station BS and two users U1 (a near-end user) and U2 (a far-end user), for the two users are located in a communication dead zone of the basestation, using RIS for auxiliary transmission, enabling the demodulation sequence of a user U1 to be prior to U2, and obtaining demodulation signal-to-noise ratios of the user ends U1 and U2; defining a security rate of the system; constructing a joint optimization equation; and dividing the joint optimization equation into two steps of beam forming and power distribution to be solved. A system comprises a power distribution module; a security rate definition module; a joint optimization equation construction module; and a joint optimization equation solving module. On the basis of combination of the RIS technology and NOMA, a joint optimization equation is established, a joint beam forming algorithm and a power distribution scheme are provided to solve the equation, and the safety rate of the system is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, and in particular relates to a joint optimization method for physical layer security in a 6G RIS-assisted NOMA system. Background technique [0002] At present: With the rapid development of society, economy and industry, people's demand for data traffic is growing explosively. The sixth generation mobile communication (6G) will be a research hotspot for future researchers, and RIS is a feasible 6G One of the communication technologies that has received extensive attention. RIS is composed of a large number of low-cost passive reflectors, which can reflect the signal from the base station, and realize passive beamforming by controlling the amplitude or phase of the reflected signal to enhance or weaken the signal. [0003] As one of the key technologies of 5G, NOMA technology has also received extensive attention. Especially the NOMA technology of power domain multiplexing, which...

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Problems solved by technology

[0008] The difficulty in solving the above problems and defects is: In the NOMA system of RIS-assisted transmission, joint beamforming and power allocation are required to construct an optimization equation to achieve the purpose of improving the security of the physical layer of the system. However, most optimization methods to solve such problems Most of the equations are non-convex and have high complexity. It is necessary to design corresponding algorithms to simplify and solve the optimization equations. There are no important related patents and related literatures for such methods.

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