空闲频谱的最优联合软判决检测算法

Cooperative detection algorithm of idle spectrum in cognitive radio

为了改善认知无线电中感知用户(未授权)对主用户弱信号的检测性能,采用多个感知用户合作的最优联合软判决检测算法。在考虑参与联合检测的感知用户门限判决相互独立的条件下,通过理论分析和软件仿真,表明在融合中心虚警概率恒定的条件下,与给定各判决门限和系统融合准则的算法相比较,最优联合检测算法性能更好。仿真结果还表明,联合检测算法随着参与感知用户数目的增加,能够改善对主用户弱信号的检测性能。当各感知用户采用软判决方法,对于2个感知用户合作和3个感知用户合作的情况,可对最优联合检测算法性能有0.5dB改善。

To improve the detection performance of sensing users for primary users （weak signals） in the cognitive radio, the optimal cooperative soft decision algorithm by many sensing users are adopted. In this paper, the thresholds of each sensing user are independent. Through theoretical analysis and simulation, the detection probability of optimal cooperative detection algorithm is better than both fusion rule and threshold decision fixed when the False Alarm probability of the fusion center is constant. The results also show that cooperative detection algorithm improves the detection performance of primary user as the attendees grow. When each sensing user adopts soft decision method, for the cooperation of two sensing users and sensing users, the performance of optimal cooperative detection algorithm has 0. 5 dB improvement respectively.