基于无线环境图信息辅助的多循环频率协作频谱感知方法

针对频谱感知中单循环频率检测不能充分利用信号循环谱信息的缺点,本文提出一种基于无线环境图(radio environment map,REM)信息辅助的多循环频率协作频谱感知方法.本文方法第1步在多个认知用户处分别选取多个相同的循环频率进行循环平稳检测,选取谱相关函数幅度作为检测统计量,根据推导的判决门限公式设定恒虚警...

Multi-cycle-frequency Cooperative Spectrum Sensing Method Based on Radio Environment Map Information

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).