To expand the coverage area of the free space optical(FSO) communication networks,the cognitive cooperation FSO communication relaying strategies are investigated.The system model of the FSO networks is that four linear nodes want to realize the two-way optical information exchange.The idea of jointing wireless network coding and superposition coding cognition receiving(JN-SCCR) is presented firstly.With the JN-SCCR concept,two different two-way relaying strategies are proposed as well as the an...