Transmission synthesis scheme for a multicast system with unknown locations of eavesdroppers

In order to solve the problem of multicast wireless secure communication with unknown locations of the eavesdroppers, a secure communication synthesis scheme was proposed based on the frequency diverse arrays. By studying the frequency diverse arrays model and analyzing the beam pattern, a random frequency diverse array is constructed at the transmitter. At the same time, combined with the added artificial noise baseband signal processing method, the maximizing artificial noise energy method is designed to optimize the beamforming weighted vector of each multicast group, so as to improve the security performance of the multicast system. Numerical results show that the scheme realizes secure communication of a multicast system and can precisely control the signal energy received by legitimate users.