A robust multiple antenna blind spectrum sensing algorithm based on rank criterion in cognitive radio

In the multiple antenna sensing scenarios, the sensing performance of the classical energy detection(ED)method shows the instability owing to the noise uncertainties phenomenon. Using the fact that the statistical covariance matrix of the multiantenna received signal is a rank-1 matrix, this paper presents a new spectrum sensing method based on the rank criterion. In the new algorithm, the sample covariance matrix of the received signal is firstly divided into an unknown ideal matrix and a perturbed matrix, and then the rank detection criterion is used to estimate the optimal dimension of the received signal space, and finally the estimated value is used to decide the channel state. Compared with the ED method, the proposed method is robust to noise uncertainty and belongs to blind detection. Specifically, the new algorithm does not need to use noise variance, the statistical characteristic of the primary user signal and the wireless channel to make a right decision. Simulation results verify the effectiveness of the proposed rank criterion based multiantenna spectrum sensing algorithm.