The classical method based on artificial noise for physical layer security cannot enhance the reliability of the legitimate user.Aiming at this problem

this paper proposes a dynamic method to generate artificial noise and glean benefit from the artificial noise for the legitimate user.The main idea is that the sender pre-generates artificial noise

then analyzing the interference of the noise to the legitimate user

the sender change the phase of received artificial noise of the legal user to align the noise and the desired signal.Analytical and simulation results show that the method proposed significantly improves the performance of legal users when the eavesdropper reached the same level of interference in both methods.