基于瑞利多径衰落信道的信号包络频谱感知

Spectrum Sensing Based on Signal Envelope of Rayleigh Multi-path Fading Channels

为提高信号采样值之间的相关性和降低噪声对感知性能的影响,该文提出基于信号包络自相关矩阵的频谱感知算法。首先对采样信号等间隔时长截取,以相邻间隔的采样值计算信号自相关性,并构造出近似自相关矩阵。其次依据矩阵次对角线元素性质构造了统计量。分别计算了该统计量的检测概率分布函数与虚警概率分布函数,分析了频谱感知算法的检测性能,算法优化了信号相关性的计算,降低了噪声对感知性能的影响。最后通过仿真验证了不同参数对检测概率和虚警概率的影响,并提出了进一步提高检测性能的措施。

In order to improve the correlation between signal samplings and reduce the influence of noise on sensing performance, a spectrum sensing algorithm based on signal envelope autocorrelation matrix is proposed in the paper. Firstly, the sampling signals are intercepted at equal intervals, the signal autocorrelations are calculated by means of the adjacent interval samples, and an approximate autocorrelation matrix is constructed. Secondly, the statistic is constructed according to the properties of the sub-diagonal elements of the matrix. The detection probability distribution function and the false alarm probability distribution function of the statistic are calculated respectively. The detection performances of the spectrum sensing algorithm are analyzed. The algorithm optimizes the calculation of signal correlation and reduces the impact of noise on detection performance. Finally, the effects of different parameters on detection probability and false alarm probability are verified by simulation, and some measures are proposed to improve detection performance.