| The article focuses on the key technology of cognitive radio frequency spectrum detection. This paper discusses how to use the difference of the polarization information of the signal and the noise for spectrum detection, and propose several polarization detection algorithms under different conditions. analyze the performance of the polarization detection on the condition of the unknown signal arrival angle information and puts forward the improved algorithm.The research work is supported by Chinese National Nature Science Foundation (NO.60902047). As an intelligent spectrum sharing technology,cognitive radio dynamicly use the frequency which the authorized user don’t occupy, and improves the spectrum utilization notably.lt solves the frequency spectrum resource issues from a new idea.An important problem of realization of cognitive radio is frequency spectrum detection. This paper introduces the research background of the subject firstly, and briefly introduces the existing spectrum detection in cognitive radio technology.And the performance of detection Are compared and analyzed. Secondly, We introduce the polarization theory and the existing detection method and theory which use of the polarization information.On the basis of the above, this paper presents spectrum detection algorithm based on polarization information making fully use of the difference of polarization characteristics of authorization user signal and noise on the receiving end. And the spectrum detection algorithm according to the likelihood ratio test theory improve the detection performance. In order to solve the problem of signal arrival angles unknown, according to the generalized likelihood ratio theory and optimization theory this paper get a improved estimation detection algorithm based on the angle of arrival and the signal covariance matrix. It effectively improves the detection performance. We summarize the thesis and put forward the direction of further research at the end. |
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