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.