中文摘要：

针对在噪声不确定通信环境下,传统双门限协作频谱感知算法在同时提高频谱检测性能与降低数据传输量中的不足,提出一种基于分步融合的双门限协作频谱感知改进算法.该算法首先对所有认知用户进行过滤,剔除深度衰落用户对检测性能的不利影响;然后根据噪声不确定度自适应设置双门限值,增强感知系统对噪声不确定环境的适应性;最后在融合中心采取分步融合的策略,合理折中高检测性能与低数据传输量间的矛盾.理论分析与仿真结果表明,与传统双门限频谱感知算法相比,该算法可完全避免感知失败,在保证低数据传输量的同时可有效提升检测性能,当噪声不确定度较大时,提升效果更明显.

英文摘要：

Concerning the shortcomings in improving the sensing ability and reducing the amount of data transmission of the conventional dual-threshold cooperative spectrum sensing under the communication environment of uncertain noise, an improved dual-threshold cooperative spectrum sensing algorithm based on two-step fusion was introduced in Fusion Center （ FC）. Firstly, this algorithm got rid of the negative influences of some drop-out users by filtering all cognitive users. Then set the dual-threshold adaptively according to the uncertainty of the noise to strengthen the sensing adaptability of system under uncertain noise circumstance. Finally, by adopting a strategy of two-step fusion in FC, this algorithm made a compromise between the high detection ability and low amount of the data transmission. Compared with the conventional dual-threshold spectrum sensing algorithm, the theoretical analysis and simulation indicate that the proposed algorithm can not only avoid the cognitive failure and enhance the cognitive performance on the condition of a low data transmission, but also show an obvious improvement under a high noise uncertainty.