分簇频谱检测报告信道的信噪比墙及性能分析

SNR Wall of Reporting Channel for Cluster-based Spectrum Sensing and Its Performance Analysis

分簇算法是感知无线电频谱检测的重要方案,它包括次级用户到簇头和簇头到融合中心2种报告信道,本文研究这2种报告信道不理想时对系统检测性能的限制。针对目前"误比特率墙"的问题,本文提出"信噪比墙"的指标。首先推导在监听信道不同信噪比和2种报告信道都不理想的情况下,系统检测概率和虚警概率的通式;然后得出报告信道上信噪比墙的存在,并分析在不同信道分布和不同调制方式下,2种报告信道的信噪比墙对系统整体检测性能的影响。仿真结果显示,理论值与仿真结果吻合,所得结论对分簇算法的设计和实际应用具有重要的意义。

Clustering is an important technique in cognitive radio networks. There are two reporting chan- nels in the cluster.the channel between the secondary users and the cluster head, and the channel be- tween the cluster head and the fusion center. This research is about the performance limitation when these two reporting channels are not ideal. Under the phenomenon of ＂BEP Wall＂,this paper puts for-ward the index of ＂SNR Wall＂. First of all,closed-form expressions for the global probabilities of detec-tion and false alarm are derived for non identical SNR on the listening channels and non ideal reporting channels. Then the existence of SNR wall is shown. Moreover,the effect of SNR wall of the system is an- alyzed under different channel distributions and different modulations. It is shown that the simulated SNR wall values are very close to that of the theoretical one. The conclusions is of great value for the de-sign of clustering algorithm.