The invention discloses an RIS-assisted
satellite-ground safety communication method with interference, and belongs to the field of
satellite-ground safety communication. The invention provides a
satellite-ground safety communication
system for RIS assistance. The satellite-ground safety communication
system comprises a
satellite transmitter, an RIS, an unmanned aerial vehicle (UAV), a
receiver and a plurality of EVEs. And the UAV is used for transmitting harmful interference signals. With safety rate maximization as a target, constraint conditions comprise a satellite transmitting power constraint CR1 and an RIS constant modulus constraint CR2, and a safety communication
system optimization problem is constructed; by taking safety rate maximization as an optimization target, the worst
receiver can also realize safety communication; effective emission of a
signal transmitter is ensured through satellite
emission power constraint CR1, and
signal reflection is ensured through RIS constant modulus constraint CR2. According to the method, the RIS constant modulus constraint CR2 and the objective function are subjected to non-convexity
processing, the
optimization problem of the security communication system after non-convexity is jointly optimized, the maximum security rate is obtained, and it is ensured that the multi-user security communication system can still communicate reliably and safely under the condition of
noise uncertainty.