【摘要】 针对认知无线电网络中由于噪声功率不确定性而影响频谱检测性能的问题,提出了一种基于模糊似然比检验的协作频谱检测方法。首先,将每个次用户(SU)中的噪声不确定性均建模为模糊假设检验(FHT);然后,在FHT上利用似然比检验构建带有阈值的模糊能量检测器,该阈值依赖于噪声功率不确定性边界;最后,在融合中心结合SU的局部硬决策并做出最终决策,从而检测主用户是否存在。通过Monte Carlo模拟受试者ROC曲线及检测概率/SNR曲线验证了本文方法的有效性,仿真结果表明,相比其他几种较新的能量检测器,本文方法获得了更好的检测性能。更多还原

【Abstract】 To solve the problem of spectrum sensing in the noise power uncertainty environments,a cooperative spectrum sensing scheme using fuzzy set theory to mitigate the noise power uncertainty is proposed. Firstly,the noise power uncertainty in each Secondary User( SU) is modeled as a Fuzzy Hypothesis Test( FHT). Then the likelihood ratio test on the FHT is deployed to derive a fuzzy energy detector with a threshold that depends on the noise power uncertainty bound. Finally,the fusion center combines the received local hard decisions from the SUs and makes a final decision to detect the absence / presence of a primary user( PU). The effectiveness of proposed method is verified by simulating ROC curve and detection proba Bility / SNR curve using Monte Carlo. Simulation results show that the proposed method has better detecting performance than several other advanced energy detectors.更多还原