衰落环境中认知无线电分布式合作频谱检测

Distributed Collaborative Spectrum Sensing of Cognitive Radio in Fading Environment

为了有效提高认知无线电中频谱检测性能是认知无线电技术的关键一步,构建了认知网络中主用户和一组次用户之间的频谱检测模型,提出了OR/AND两种检测融合准则,并对两种检测融合准则下的检测概率进行了比较。基于准则,进一步具体研究了Rayleigh衰落环境中,针对信噪比(SNR)变化,分布式合作节点数量变化等不同系统参数对提高频谱检测性能的影响。给出了Rayleigh衰落环境下,各参数影响接收机工作特征(ROC)和整体检测性能的仿真分析。结果表明:一定数量的节点可有效抵消衰落对ROC性能造成的影响,使其在低SNR条件下仍获得较高的检测概率。

How to improve the spectrum sensing performance is one of the most crucial steps in cognitive radio （CR）, the paper builds a model for primary user detection in a simple multi -user cognitive network. The OR/AND decision fusion rules on the spectrum sensing protocols employed by CR are proposed, and the sensing performance in these rules are compared. Based on the rules, the paper analyses the influences of different parameters such as detection provability, local SNR, number of spectrum sensors on the spectrum sensing performance in Rayleigh fading environment. Furthermore, the receiver operating characteristic （ROC） and the throughput in different parameters in Rayleigh fading environment are simulated. The analysis and simulation results indicate that fusing decisions of different secondary users can cancel the deleterious impact of fading effectively, and get better spectrum sensing performance even under low SNR.