在协作频谱感知中,当信道经历衰落和阴影时,各用户的感知性能会有不同程度影响,某些受影响严重的次用户甚至可能会严重影响到整个感知网络的性能。同时参与协作的用户数越多,认知传感器网络面临的问题越大。为了解决这些问题,提出了一种基于能耗的分簇协作感知算法。该算法引入基于节点能量的LEACH分簇算法,将认知传感器网络中的各个节点按该分簇算法分入若干簇内;在每个簇内,构造了同时考虑检测性能和能量消耗的效用函数,基于该效用函数对最佳协作用户数和用户进行选择,使每个簇内的检测性能和能耗达到很好的折中;在汇聚节点运用OR规则将簇头发送过来的感知信息进行融合,得到最终判决结果。仿真结果表明,该基于能耗的分簇协作频谱感知算法可以有效地延长认知传感器网络的生存时间,节省网络的能耗,并且保证良好的检测性能。
In cooperative spectrum sensing,each secondary user's sensing performance is affected in different degrees when the channel experiences fading and shadow.Some severely affected cognitive users may even reduce the entire sensing performance of the cognitive sensor networks seriously.At the same time,the more the number of users involved in cooperation,the larger problems that cognitive sensor networks should face.To solve these problems,a cooperative spectrum sensing algorithm based on energy consumption is proposed.The algorithm introduces the LEACH protocol based on the node energy dissipation.All the nodes of the cognitive sensor network are divided into a number of clusters in clustering algorithm.And within each cluster,a utility function is constructed to decide the optimal number of cooperative users and choose the users involved in collaboration by taking into account the detection performance and energy consumption.So that detection performance and energy consumption in each cluster can achieve a good compromise.Informations received from cluster heads are fused to obtain the final decision applying OR rule in the sink.Simulation results show that the cooperative spectrum sensing algorithm with energy consumption can effectively prolong the survival time of cognitive sensor networks,reduce energy consumption of networks and ensure a good detection performance.