Cognitive radio has become an adequate approach to solve the inefficiency of the spectrum utilization by accessing the radio spectrum strategically. In this paper, adaptive multistage wiener filter is used for the detection purpose. With the designing of such filter, detection performance is boosted because of picking up of the signal report and abolishing the additive noise. Meanwhile, in this scheme estimation of the complex matrices as well as the eigenvalue from covariance matrices is not required. Thus this system achieves a low computational complexity. Unlike conventional algorithms, neither noise power estimation nor prior knowledge of primary user signal is needed. All these qualities make the proposed algorithm robust to noise uncertainty and suitable for unseeing detections. Simulation results illustrates how reliably the unused spectrum can be detected with an acceptable trade-off. In other words, the fundamental aim is to increase detection probability and minimizing the complexity

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Cognitive Spectrum Frequency Bands