The invention provides a
physical layer secure transmission method based on an unmanned aerial vehicle assisted cognitive
wireless network, and belongs to the field of
wireless communication. The method specifically comprises the following steps: establishing a
wireless communication scene comprising an unmanned aerial vehicle, a primary user
transmitter, a primary user
receiver, a secondary userreceiver and an eavesdropper, and then, in a
frequency spectrum sensing time tau of a time slot T, enabling the unmanned aerial vehicle to perform spectrum sensing, wherein the main user may perform
data transmission, and calculates the safe
transmission rate at the moment; meanwhile, in the
data transmission time period Ta of the time slot T, enabling the unmanned aerial vehicle to judge the access state of the current main user channel based on spectrum sensing, selecting the current main user channel as a friendly interference unit or a secondary
signal transmitter, and discussing a securetransmission model in four situations; based on this, formulating an optimization model of the total
secure transmission rate; performing solving by using a
particle swarm optimization algorithm; andenabling the unmanned aerial vehicle to perform
signal physical layer safety transmission according to the obtained optimal parameters. According to the invention, the
secure transmission of the primary and secondary users is considered, so that the secure
transmission performance of the
system is improved.