Research On Cooperative Spectrum Sensing Method Based On Multicycle Frequency In Cognitive Radio

As a kind of intelligent spectrum sharing technology,cognitive radio(CR)technology can make rational use of idle frequency band for communication,which has been widely concerned in today's increasingly scarce spectrum resources.Spectrum sensing is not only the first step to realize spectrum sharing,but also the key step to realize spectrum sharing.This paper mainly focuses on spectrum sensing technology,and improves the performance of the detection by making full use of the authorized user information on the basis of the cyclic stationary feature detection.The main work of this paper is as follows:(1)This paper introduces the background of cognitive radio.The local spectrum detection and multi-user cooperative spectrum detection are analyzed in detail.(2)The sensing method based on cyclic spectrum is discussed.Aiming at the disadvantage that single cyclic frequency detection can not make full use of the cyclic spectrum information in cyclostationary feature detection,a cooperative spectrum sensing method combining multiple cyclic frequencies is proposed to improve the sensing performance by making full use of multiple cyclostationary features and multiple cognitive user information.(3)The cooperative spectrum sensing method based on information assistance is studied.This method improves the detection performance by sharing the information of multiple cognitive users and making full use of multiple cyclostationary features of authorized users' signals.At the same time,considering the problem of decision credibility at cognitive nodes,the wireless environment graph technology is used as an information support for cognitive radio system to conveniently obtain the decision confidence weight at each cognitive node,and the weighted fusion is used to improve the detection probability,so as to improve the overall performance of cognitive radio system.(4)A communication signal receiving platform based on software radio is built.At the same time,the interface of 802.11a upper computer system is realized.The simulation and experimental results show that the joint detection of multiple cyclic frequencies can make full use of the multi cyclostationary features of the signal.When considering the decision credibility at the cognitive node,the information aided detection method does not need to consider the cognitive user's own SNR information,and has good detection performance under the condition of low SNR;In addition,The software radio platform can effectively receive communication signals and calculate cyclic spectrum.