Cognitive Radio Cooperatively Detect Spectrum By Energy Detection Spectrumin Rayleigh Fading Channels

With communication by voice to multimedia applications, the increasing demand for high-speed wireless transmission.However, the existing static frequency allocation mechanism can not meet the requirements of a rapid surge of high-speed communication device, due to the limited natural spectrum. Therefore, you need to be able to improve spectrum utilization efficiency, innovative technology, and the emergence of cognitive radio to solve the spectrum congestion problem, this paper will examine the energy detection spectrum sensing threshold decision method in cognitive radio networks, decision-making the center receives multiple cognitive radio observations value, decision to determine whether the presence of the primary user.The article focuses on the theory of cognitive radio to make the introduction, at the same time introduce key technologies:cognitive radio spectrum sensing, spectrum management, spectrum sharing on the process of the development of cognitive radio technologies. Followed by detailed spectrum sensing of cognitive radio system, first described the concept as well as the characteristics of the multi-dimensional spectrum, and then do the spectrum analysis of the key points from these different dimensions, and derive the spectrum can be used as application-aware algorithm, at the same time explore the perception the spectrum process may encounter some difficulties and challenges, then some classic spectrum sensing method are introduced.Spectrum sensing scheme, select cooperation perception analysis, research cooperation perception in Rayleigh fading channels cognitive radio uses energy detection spectrum, the first detailed study of the energy detection method, carried out the theoretical analysis and simulation experiment, the false alarm rate and detection probability is derived, and compare the two indicators of change under different signal-to-noise ratio curve. After introduction of Rayleigh fading belief Road’s features, at the same time proposed in this channel environment carried out emulation of significance, and then through the analysis traditional cooperative perception,derivation of a able to improve the system discriminant accuracy departments limit of detection of the way, and the key indicators The theoretical and simulation analysis,Studies show that the the detection energy cooperation in Rayleigh channel spectrum sensing threshold judgment perception effect can be enhanced.