The invention discloses a self-adaptive safety
communication device and method based on vortex electromagnetic
waves, and relates to the technical field of
wireless communication. Generating a direction
radiation coefficient table of the N-element uniform circular ring
antenna array under a given carrier frequency; adaptively selecting an orbital
angular momentum mode for sending the
artificial noise; orbital
angular momentum modulation of the sending
signal and the
artificial noise; the invention relates to coaxial multimode
multiplexing transmission of orbital
angular momentum. According to the invention, the secure
wireless communication can be realized by using only one uniform circular ring
antenna array. The
artificial noise is multiplexed in a non-
zero mode, so that legal users are not interfered, the
channel capacity of eavesdroppers is reduced, and high-capacity secret communication is realized. Meanwhile, according to the
direction angle information of the eavesdropper, the optimal mode of the artificial
noise is adaptively selected, the eavesdropper is shielded to the maximum extent, and the secrecy performance of the
system is improved. And when the direction of the eavesdropper is unknown, a mode of random hopping of an artificial
noise mode is adopted to shield potential eavesdroppers in all directions, so that the secrecy capacity of the
system is improved.