Research Of Cooperative Spectrum Sensing Technology Based On D-S Evidence Theory

With the development of wireless communication technologies, the contradiction between the allocation policy and the usage of the spectrum is realized by more and more people. Cognitive radio (CR) break the bottleneck of the increasingly shortage of spectrum resources by reusing the licensed spectrum, so in the field of the wireless communication networks, it has been widely recognized as one revolutionary technology of the intelligent spectrum sharing. Spectrum sensing (SS) is one key technology of CR, which paves the way for the realization and practical application of CR, as a result, spectrum sensing (SS) receives widespread attention.The thesis analyzes the concept of CR technology, the development and current situation of the domestic and foreign research, and the spectrum sensing technologies which are usually used, laying a theoretical foundation for the thesis. Detect the usage of spectrum efficiently and reliably is the fundamental role of SS. Local SS could not always guarantee the performance requirements due to such constraints as channel fading, shadow effects and noise uncertainties. As a consequence, cooperative SS which utilizes sensing information from multiple users become the focal point and the central issue because solve these problems effectively.This thesis focuses on the problem of cooperative SS, in the areas of the SS technologies which are usually used, the effects of control channel environment on SS, the information fusion technologies of cooperative SS, and the evidence theory’s application in cooperative SS.First, sensing data fusion in cooperative SS is analyzed, and then cooperative SS techniques are discussed from the ideal and the non-ideal two angles of the control channel environment, analysis that the cooperative spectrum sensing performance when control channel exist transmission error. Secondly, because the problem of different sensing nodes are in different wireless environment is not found, which are not considered in previous cooperative SS algorithms. The Dempster-Shafer (D-S) evidence theory is introduced to SS technology, and cooperative SS process is discussed in detail based on the D-S evidence theory. Finally, this thesis analyze cooperative SS scheme based on D-S evidence theory through the simulation. The simulation results show that this algorithm has better sensing performance and stronger robustness than the traditional cooperative SS, regardless of the environment of Cognitive User (CU) are same or not.