Abstract:Given that single-cycle frequency detection cannot make full use of the cyclic spectrum information in spectrum sensing, this study proposes a multi-cycle frequency cooperative spectrum sensing method based on radio environment map (REM) information. The first step of this method is to select multiple same cyclic frequencies at multiple cognitive users for cyclostationary detection. The spectral correlation function amplitude is adopted as the detection statistic. The threshold value at a constant false-alarm rate (CFAR) is set according to the derived decision threshold formula, and the detection result at a single cognitive user is obtained through decision fusion. In the second step, the weight coefficient at each cognitive node is calculated according to the distance between the authorized user and the cognitive user provided by the REM. Weighted fusion of the weight coefficients and the detection results of the corresponding nodes are conducted to improve the reliability of the detection results. Simulation results show that the improved method can effectively detect authorized users and has better detection performance and stronger practicability under a low signal-to-noise ratio (SNR).