Physical layer secrecy method for RIS-assisted wireless communication

The invention discloses a physical layer secrecy method for RIS-assisted wireless communication. The physical layer secrecy method comprises the following steps: step 1, designing an RIS-assisted communication system scene; 2, designing a main link; 3, planning an eavesdropping link; 4, designing a secret communication model; and 5, analyzing a simulation result. In the invention, the PLS (Partial Least Square) of RIS (Radio Information System) assisted wireless communication under the conditions of discrete phase shift and passive Eve is studied. In RIS-assisted secure communication, the position distribution of passive Eve is considered for the first time. Information obtained from Alice or signals received from RIS reflection are eavesdropped from the perspective of Eve, two situations that Eve is distributed outside/inside the RIS direction are discussed, and CDFs of SNRs received at the Eve are deduced respectively. Based on the derived CDF, a closed expression of non-zero secrecy capacity probability an