在IEEE802.22标准系统模型下分析了最优合并准则的性能及影响因素.在此基础上提出了用户删除的方法:通过设置门限去除对最终判决影响较小的用户,从而大幅减少了合作感知的反馈信息,有效节省了反馈信道资源.理论分析和仿真结果显示,用户删除通过设置合理的门限可有效控制系统的性能损失,同时降低反馈信道资源需求,为进一步的系统优化打下了基础.
Cooperative sensing can effectively improve the performance in cognitive systems,and the main benefit comes from some high reliable users but not all users. The performance of the optimal fusion rule is analyzed under the system model of IEEE 802. 22. Based on the analysis,a new user rejection algorithm is proposed to reduce feedback resource greatly with limited performance loss. The proposed sets a threshold to reject users with low reliability. Analysis and simulation show that the user rejection can effectively control the system performance loss by setting a reasonable threshold. Moreover,it also reduces the requirements of feedback channel resources and provides a foundation for further cooperation sensing system optimization.