Technology of spectrum access in the cognitive radio
Lu Zhen · Information technology newsletter · 2009
Cognitive radio,built on a software-defined radio,is an intelligent wireless communication system.It is aware of its environment,and by some method it can correspondingly change some working parameters to adapt to the environment in real time.Its objectives are to efficiently utilize the radio spectrum and solve the problem of radio electromagnetic spectrum scarcity.The use of spectrum in authorized spectrum band is one of the key technologies of realizing cognitive radio.In this paper,dynamic spectrum access and opportunistic spectrum access have been studied,which are the two methods of spectrum usage in the authorized spectrum band.