Research On Spectrum Sensing Technology In Heterogeneous Cognitive Networks

With the rapid development of wireless communication technology,wireless communication system is going through changes and updates,from homogeneous network to heterogeneous networks that include different evolution routes and different wireless access technologies.However,just like homogeneous network,heterogeneous networks also face the same technical problems,that is scarcity of spectrum resources.Therefore,it is of great significance for the development of wireless communication technology to optimize the allocation of spectrum resources and improve the utilization ratio of spectrum resources.Considering the low utilization ratio of spectrum resources in heterogeneous network,we use cognitive radio technology to detect spectrum hole and give a more reasonable use to them to improve spectrum utilization ratio and ease the shortage of spectrum resources in heterogeneous cognitive network.Firstly,this paper introduces the present situation,trend and key technologies of cognitive radio technology.Then take spectrum sensing technology in cognitive radio as the research object,make a detailed introduction to the common spectrum sensing technology,especially focus on the single node spectrum sensing technology,analyse the detection probability and false alarm probability of different spectrum sensing algorithm,and finally summarizes their advantages,disadvantages and applicable scenariosIn order to solve the problem of the lack of spectrum resources and the low utilization ratio of spectrum in heterogeneous cognitive networks,the following work are carried out in this paper: on one hand,this paper carries out research work which based on the traditional double threshold energy detection,especially on the influence of noise uncertainty to the traditional double threshold energy detection,and deduces the system detection probability and false alarm probability of scheme which consider the uncertainty noise.Analysis results show that the proposed cooperative spectrum sensing method for double-threshold energy detection based on noise uncertainty do reduce the effect of noise uncertainty on the performance of energy detection,and doesn't need more overhead transmission.Simulation results show that the proposed cooperative spectrum sensing method for double-threshold energy detection based on noise uncertainty is a feasible spectrum sensing scheme.In order to set the threshold of double threshold energy detection properly,on the other hand,this paper carries out research work which based on the traditional double threshold energy detection,especially on the influence of threshold dynamic variation on the performance of energy detection,and deduces the system detection probability and false alarm probability of scheme which consider the variation of threshold dynamic.Analysis results show that the proposed cooperative spectrum sensing method for double-threshold energy detection based on variation of threshold dynamic considered the dynamic change of the threshold and the environmental factors,it has strong adaptability to the complex and changeable environment.Simulation results show that the proposed cooperative spectrum sensing method for double-threshold energy detection based on variation of threshold dynamic do improve the detection performance of the system and have higher antinoiseperformance.