Research Of Spectrum Sensing Algirthm In Cognitive Radio Network

The Research are supported by the National Natural Science Fundation "Research on spectrum detection based on spectrum utilization statistic"(NO.60772110),and Huawei Technology Fundation "Research about cognitive radio in MAC Layer"As a revolutionary smart spectrum sharing technology,CR can significantly improve the spectrum utilization and becomes more and more popular in recent years.In the CRN,CR users can automatically sense the wireless environment,and then access the CRN within the spectrum which had been allocated to the licence users but not occupied right now.The key point in CR technology is spectrum sensing ("spectrum detection" is also used),i.e.how to find the spectrum hold and identify the licence users.In this paper,the subject background and significance of CR is showed firstly.And secondly the spectrum sensing model is described, the typical spectrum sensing algorithmsare comparied.The impact of spectrum sensing under shadowing/fading environments and noise uncertainty,as well as the effect of the selection of data fusion and decision algorithms,shadowing correlation,the presence of untrusted users on detection performance of cooperative spectrum sensing is discussed.And the spectrum sensing mechanism algorithm is analyzed with emphasis.At last,two new spectrum sensing strategies based on linear programming is proposed,which is full use of the differential of the primary user's signal strength,to improve the performance of sepectrum sensing.By the simulation,the proposed strategies,based the current hardware codition,could effectively improve the performance of the spectrum sensing.Meanwhile,the object to protect the primary user and increase the efficiency of the spectrum is reached.