Rate segmentation multiple access physical layer secrecy method based on friendly interference

The invention discloses a rate division multiple access physical layer secrecy method based on friendly interference. A base station firstly sends a pilot signal to a primary user and a secondary user and carries out channel estimation; secondly, the main user feeds back the transmitting power and the estimated channel state information to the base station; the base station calculates the maximum interference threshold tolerated by the primary user according to the received feedback information and sends the maximum interference threshold to the secondary user; the secondary user combines the transmitting power and the channel gain, compares the transmitting power and the channel gain with an interference threshold at the primary user, and calculates a transmitting power distribution coefficient and a target rate distribution coefficient according to a comparison result; then, in order to improve the security of data transmission of the secondary user, the main user sends artificial noise to interfere with th