一种自适应的协作频谱感知方法

An Self-adaptive Cooperative Spectrum Sensing Scheme

在认知无线网络中,协作频谱感知技术可有效提高衰落信道下的检测性能,提高对主用户的保护程度以及认知用户的接入机会。在信道状态良好的情况下,参与协作的认知用户数越多,感知性能越好。而在实际的频谱感知过程中,如果感知信道条件较差的话,认知用户的本地感知结果并不准确,此时该认知用户的本地感知结果对于总的协作感知并不能起到积极的作用;其次,参与协作的认知用户数越多,发送本地决策值占用的系统带宽也越大。为了节约系统资源避免不必要的信令传输,本文提出一种自适应的协作频谱感知方法,只有当认知用户的感知信道条件较好时才将其本地感知结果发送到融合中心,否则不发送,以节约系统资源。最后,通过仿真验证了所提方法的有效性。结果表明,所提方法可有效节约系统开销。

In cognitive wireless networks,cooperative spectrum sensing can effectively improve the detection performance under fading channels and enhance the protection ability to primary users and the access chance of cognitive users. More cognitive users will make the better sensing performance when the channel conditions are better.While in actual spectrum sensing,the local sensing results of cognitive users maybe not accurate if the sensing channels are destructive,which will play no part in total cooperative spectrum sensing. Secondly,more cognitive users that take part in cooperation will lead to the more system bandwidth occupied for sensing local decision results.In order to save system resource and avoid the unnecessary signal transmission,we propose an adaptive cooperative spectrum sensing scheme,in which,only when the sensing channel conditions are better,the cognitive users will send local sensing results to the fusion center so as to save system resources. The simulation results validated the proposed scheme. The results indicate that the system expense can be effectively saved by the proposed scheme.