The Research Of Spectrum Sensing In Cognitive Radio

The relative scarcity and waste made the situation of the limeted wireless spectrum resource more tense. How to improve wireless spectrum efficiency to the maximum has become a technical problem that needed to be solved urgently.Cognitive radio technology is proposed to solve the problem。Spectrum sensing technology is a key implementation technology of Cognitive Radio.It reflects the most essential characteristic of Cognitive Radio,that is,able to sense and analyze the frequency band in a specific region and find the suitable spectrum holes.According to the number of cognitive users,spectrum sensing technology can be diveded into single-user spectrum sensing technology and multi-users cooperative spectrum sensing technology.Firstly,several existing single-user spectrum sensing techniques were summed up and analyzed,such as matched-filter detection,waveform detection,energy detection, cyclostationary detection,entropy-based detection and maximum eigenvalue detection.Especially,the capability analysis of energy detection was emphasized,which would be used in the following chapters.Secondly,this paper studies the single-user spectrum sensing technique based on energy detection in different channels,such as: Gauss channel, Rayleigh channel,Rician channel and Nakagami channel.Also in this paper some differents of detection capability in these channels are gived.Thirdly, this paper studies the arithmetic based on hardware fusion in cooperative spectrum sensing.Then makes the theoretical analysis and simulation of cooperative sensing on"AND"rule,"OR"rule and"K/N"rule.Finally,in Chapter 5 this paper studies the capability of cooperative spectrum sensing when the control channel is not reliable.Low bound of false alarm will appear when the control is not reliable.Then this propose a arithmetic based on error correction coding and a group-based arithmetic to improve this problem,also this paper makes a simple comparison of these two arithmetics.The innovation section of this article is in this chapter.