| In recent years, with the continuous development of wireless communication technology, the spectrum needed by the developing wireless communications service becomes more and more, which causes the shortage of wireless spectrum resource, the development of wireless communications service is restricted by the traditional rule of static spectrum using. Cognitive radio is considered to be the wireless communication technology to solve the situation of spectrum emergency, and is mainly one of network technology of the next generation of wireless network. In the cognitive wireless network, this technology can use spectrum detection to perceive the wireless spectrum environment, and conclude the spectrum condition through the intelligent learning and decision making. It improve wireless spectrum utilization by dynamic spectrum access. The key of improving spectrum efficiency co is highly efficient spectrum perception, and using dynamic spectrum access to complete communication. There is so much research on cognitive radio over the world, but most of them are based on theoretical research and simulation, which lacks of practical platform to verify. So an actual platform based on cognitive radio is of great significance to the study of this technology.This paper introduces d the concept of and the key technology of cognitive radio or software defined radio, and design a set of cognitive radio system based on GNU Radio and USRP. This paper introduces the realization of the GNU Radio function the structure USRP, and emphasis on the realization of the platform. The spectrum sensing technology, transmission theory, dynamic spectrum access technology are introduced, too. The realization of this technology based USRP was analyzed, and the corresponding programs are written while the research of this paper. At the end, the three module are joint to realize the function of the cognitive radio system. The experimental results show that the communication system can complete data transmission. |
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