关键词： 认知无线电, 盲频谱感知, 最大-最小特征值之比, 取样协方差矩阵, 随机矩阵理论

Abstract:

The blind spectrum sensing algorithm based on the ratio of the maximum and minimum eigenvalues (MME) has attracted much attention in cognitive radio (CR).One of the main advantages of this method is that no prior information of the wireless channel,the noise variance and the primary signal pattern is needed in the process of spectrum sensing.However,the determination of the corresponding decision threshold for MME method is still a difficult problem in practical applications.In this paper,a new MME method based on the improved decision threshold has been proposed.The proposed MME algorithm can obtain more reliable detection performance than the original algorithms.Simulation results verify the effectiveness of the proposed MME method.

Key words: Cognitive radio, blind spectrum sensing, the ratio of the maximum and minimum eigenvalues (MME), the sample covariance matrix (SCM), random matrix theory (RMT)