【摘要】 频谱感知是认知无线电的关键技术之一。在信噪比较低并且对主用户信号先验知识知道较少的情况下,主用户检测对于认知无线电设备来说是非常重要的。对有噪MFSK信号在循环频率处基于一阶循环矩检测器的性能进行了较为深入的理论分析,并推导了采样长度有限时噪声一阶循环矩幅度及有噪MFSK信号在循环频率处一阶循环矩幅度的概率密度函数公式;据此给出了该检测器的ROC特性曲线计算方法。理论分析表明,随着采样长度的增加,该检测器的性能显著提高;同等条件下,随着MFSK信号进制数M的增加,检测器性能有所下降。更多还原

【Abstract】 Cognitive Radios represent a powerful technology for improving the utilization of radio spectrum resources.Detection of low signal-to-noise ratio(SNR)signals with relaxed a priori information on the signal parameters is very important for cognitive radios.In this paper,an in-depth theoretical analysis is performed for the detector which can detect MFSK signals with noise based on first-order cyclic moment.For this detector,when the sampling length is limited,we derive a first-order cyclic moment amplitude probability density function formula for MFSK signals with noise and noise in the cycle frequency.Then this paper proposes a calculation method of this detector Receiver Operating Characteristic(ROC)curve.Theoretical analysis shows that with the increase of sampling length,the performance of detector based on first-order cyclic moment is improved obviously;under the same conditions,with MFSK signals dimension M increasing,the detector performance decline somewhat.更多还原