共查询到18条相似文献,搜索用时 62 毫秒
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在协作式认知无线电频谱感知中,恶意节点会通过向数据融合中心传送虚假的感知信息来降低整个网络的频谱感知性能.为了提高协作感知对虚假感知信息攻击的免疫力,提出一种基于加权序贯似然比检测技术的鲁棒协作式频谱感知方案.通过采用信誉记录,权值分配和多线程检测三种机制,能够做到有效判别和剔除恶意节点,提高了协作式频谱感知的鲁棒性. 相似文献
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认知无线电网络中的一种新型协作频谱感知方法 总被引:2,自引:0,他引:2
提出一种能够应用于认知无线电网络中的新型协作频谱感知方法--双阚值能量检测,该方法同时利用了次要用户的接收信号能量和局部判决结果两种信息,由判决中心结合次要用户的局部判决结果和接收信号能量,做出最终判决从而确定主要用户存在与否.该方法在通信流量增加不多的情况下能够充分提升检测性能.仿真结果表明当接收信号能量落入延迟判决区间的概率较大时,该算法能够显著地改善认知无线电网络的协作频谱感知能力. 相似文献
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针对同时使用硬合并和软合并的两步协作频谱感知方法在第二步的软融合时仍需向融合中心发送大量不必要数据的问题,引入了接收信噪比估计,提出了一种改进的两步协作感知算法。改进算法在低信噪比情况下使用传统的两步协作检测提升检测性能,在较高信噪比情况下则采用硬融合策略来减少发往融合中心的信息量。仿真结果表明,改进算法和传统的两步协作检测算法相比,能在几乎不损失检测性能的情况下,显著减少不必要的数据传送。 相似文献
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《计算机光盘软件与应用》2013,(2):154-155
随着无线通信技术的迅猛发展,频谱资源短缺的问题越来越严重,甚至可能成为未来制约无线通信技术发展的瓶颈。认知无线电技术通过对频谱资源的"二次利用",为缓解频谱资源紧缺开辟了一条新的路径。在认知无线电网络中,当认知用户感知到目标频段处于空闲状态时,可以接入该频段进行通信,一旦检测到主用户重新出现时,要及时做出避让,以免影响主用户的正常工作。由此可知,频谱感知技术是保证认知无线电技术得以实现的关键和前提。 相似文献
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基于可信度的认知无线电协同频谱检测 总被引:1,自引:1,他引:0
认知无线电中随着参与协同检测的认知用户数目的增大,频谱检测性能逐渐增强。但是过多的认知用户参与协同检测,会使整个认知无线电网络的灵敏度降低,同时也会造成巨大的系统开销。针对上述问题,提出了一种新的基于可信度的协同频谱检测方法。在满足目标错误概率的条件下,该算法只选择可信度较高的一些认知用户参与协同频谱检测。仿真结果表明当认知用户中存在恶意节点或者故障节点时,该算法同传统算法相比较,频谱检测性能更好,具有更强的健壮性。 相似文献
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In this paper, a novel multiple-user cooperative spectrum sensing (MCSS) scheme is proposed to achieve the spatial diversity gains for cognitive radio (CR) networks, where only the best relay, selected among all the candidate relays in accordance with the quality of channel conditions, is utilized to cooperatively detect the primary user. Closed-form expressions of detection time for the traditional non-cooperative and the proposed MCSS schemes are derived over Rayleigh fading channels. In addition, numeric... 相似文献
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QIN Ji-xin ZHANG Shi-bing 《通讯和计算机》2008,5(11):37-41
The radio frequency spectrum is a scarce natural resource and its efficiency has attracted lots of attention in both academia and industry. A fundamental problem facing the future wireless systems is where and how to find suitable spectrum bands to satisfy the demand of the consumer's insatiable appetite for data rate and enable new consumer market segments. A promising technique to improve the spectrum utilization is the ultra-wideband access based on cognitive radio (UWB-CR). Spectrum sensing, as a key enabling functionality in cognitive radio networks, needs to reliably detect signals from primary radios to avoid harmful interference. This paper is focused on the spectrum sensing technique. First, architecture of UWB-CR system was proposed. Then an overview of the spectrum sensing schemes was provided and compared. It is concluded that the optimal spectrum sensing scheme for UWB-CR system is the matched filter detection. 相似文献
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提出了一种在认知无线网络控制信道带宽受限条件下基于信任度的双门限协同频谱感知算法。首先每个认知用户基于双检测门限独立进行频谱感知,但只有部分可靠的认知用户通过控制信道向认知无线网络基站发送本地感知结果。当所有的用户都不可靠时,选取信任度最高的认知用户发送本地感知结果进行判决。理论分析和仿真表明,同常规能量检测算法相比较,该算法能够在控制信道带宽受限条件下,以较少的网络开销获得更好的频谱感知性能。 相似文献
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Cooperative spectrum sensing based on stochastic resonance in cognitive radio networks 总被引:2,自引:0,他引:2
A new censoring cooperative spectrum sensing scheme based on stochastic resonance(SR)technique in cognitive radio(CR)network is proposed in this paper.The observations of the cooperative secondary users(SUs)whose statistics fall into the censoring interval are processed by SR system in the proposed scheme.The hard fusion and the soft fusion for the censoring cooperative spectrum sensing scheme are analyzed respectively.Theoretical analyses and simulation results show that the proposed censoring cooperative spectrum sensing scheme has the same detection performance as and lower computational complexity than the method that each cooperative SU performs spectrum sensing using SR-based energy detection,and its detection performance is superior to that of the conventional method that all the cooperative SUs perform spectrum sensing using energy detection in hard fusion.In soft fusion,the proposed censoring cooperative spectrum sensing based on equal gain combination can achieve the optimal sensing performance approximately. 相似文献
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To enhance the spectrum sensing performance in cognitive radio system, a new cooperative spectrum-sensing scheme by using inactive secondary users (SUs) is proposed. Cooperative sensing is performed among SUs only when they have data to transmit. The inactive SUs have been introduced to cooperation group in the event that there are no enough active SUs to obtain the predefined spectrum detection performance cooperatively. Both the theoretical analysis and simulation results demonstrate that the performance of the trade-off between the time period used for sensing and the achievable throughput can be improved by utilizing the inactive SUs. The optimized additional listening time for inactive SUs can be obtained after the weights of the achievable throughput and the efficiency are determined. 相似文献