中文摘要：

提出将贝叶斯风险作为认知无线电系统一种新的评价标准。在这种评价标准中,考虑了主用户频谱使用率、判决结果代价等诸多因素,较传统的系统评价标准考虑更全面。针对单用户系统和多用户系统,分析了在新的评价标准下,系统如何才能获得最佳系统检测性能。仿真结果表明：单用户系统通过选择最佳判决门限,多用户系统通过选择最佳决策,可以获得最佳系统检测性能。

英文摘要：

In this paper,the Bayes risk is proposed as a new evaluation criteria of cognitive radio systems.The evaluation criteria,in which the spectrum utilization of primary users,the cost of judgments and other factors are considered,is more comprehensive than the traditional one.For single-user systems and multi-user systems,we analyze how these systems can get the best detection performance of systems in the new evaluation criteria.Simulation results show that： a single-user system can choose the the best decision threshold,and a multi-user system can select the best decision,so that we can get the best detection performance of system.