Cognitive orthogonal cooperative transmission method in the presence of primary user interference

The invention discloses a cognitive orthogonal cooperative transmission method in the presence of primary user interference mainly in order to solve the problem that the reliability of the transmission is low in the presence of primary user interference in the prior art. The method comprises the following steps: (1) a secondary user source node broadcasts a pilot signal; (2) a secondary user destination node decodes the received signal, and checks the decoded signal; if check succeeds, the secondary user destination node sends data; or, relay nodes decode the received signal and check the decoded signal; if decoding fails, the relay nodes do not forward information any longer; or, the relay nodes send the pilot signal, and the destination node returns a response signal; (3) the relay nodes select optimal relay decoding according to the received signal to interference and noise ratio, and forward an orthogonal copy of the source node information to the destination node; and (4) the destination node merges the