Research on Key Technologies of Dynamic Spectrum Access in Cognitive Radio

Research on spectrum sensing and spectrum switching that are the key technologies of cognitive radio dynamic spectrum access is carried out in this paper. In order to reduce the required number of dualistic detection when in low spectrum occupancy rate and reduce the complexity of wideband spectrum sensing calculation, this paper presents a wideband spectrum sensing method based on group testing (GT) and constructs a two-step GT scheme based on polyphase filtering. In terms of spectrum switching, a method based on spectrum prediction is proposed for the determination of the switching time. Test results show that the main function of dynamic spectrum access is changed into reality. Both sides of the cognitive radio test platform could automatically find the idle channel link and establish links without common control channel, furthermore, when the current communication channel is reoccupied by primary users, the platform could switch to other idle channel automatically and quickly.