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认知无线电(cognitive radios, CRs)主要用于克服无线通信频谱资源的短缺问题,使次用户在不干扰主用户的情况下获得对空闲频谱资源的使用。CRs中谱感知方式可通过非协作或协作的方式实施,本文研究的是一群次用户通过协作的方式实施频谱感知的情况。协作方式可以避免和改善影深和遮掩衰落对检测结果的影响,另外空间分布的用户具有更好的区域覆盖性,有助于提高准确度。
CRs中频谱感知[1]主要有3种方式:匹配滤波理论最优,但需要主用户先验信息;能量检测次优,它简单易实施,对主用户没有太多要求;循环平稳特征检测方法能够检测信噪比(signal to noise ratio, SNR)很低的信号,但它也需要主用户的先验知识[2]。文献[3]提出了分布协作感知,通过分布的次用户协作达到共识并最终判决,特别适应网络中无线衰落严重的用户检测,但是并没有考虑和利用网络拓扑资源。随着无线通信的发展,CRs技术和应用得到广泛关注,文献[4]研究了时变衰落信道下认知无线电技术;文献[5]利用CRs技术改善工业环境中干扰的影响;文献[6]研究了CRs协作信息传递时的信息碰撞问题。近年来,网络拓扑可知理论用于改善网络性能,得到关注和研究[7-9]。连通支配集(connected dominating set, CDS)是网络拓扑的重要方面。文献[9]研究了无线ad hoc网络高效路由机制,提出了连通支配集的简单有效计算方法,以及拓扑改变时的动态更新/重算方法。
本文将文献[3]与文献[9]中的方法相结合,在原算法中考虑了网络拓扑的有利因素,提出基于连通支配集的分布式协作共识频谱感知方法。
Distributed Consensus Cooperative Spectrum Sensing Method Based on Connected-Dominating-Set
doi: 10.3969/j.issn.1001-0548.2017.05.004
- Received Date: 2016-04-12
- Rev Recd Date: 2017-06-02
- Publish Date: 2017-09-01
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Key words:
- cognitive radios /
- connected dominating set /
- cooperative spectrum sensing /
- consensus
Abstract: Aiming at the problems of large amount of information exchange, slow convergence and unstable convergence result of the original whole-network distributed cooperative consensus method, a distributed consensus cooperative spectrum sensing method based on connected-dominating-set is proposed. In this paper, the connected-dominating-set method collects information of network spectrum sensing and does consensus calculation through the network connected dominating subset, which gets a stable consensus result. Then, the consensus results are shared to other non-dominated nodes in the network, so rapid convergence is achieved. There are two advantages of the proposed method compared with the original network distributed cooperative consensus method. One is that the amount of information exchanged among network nodes reduces, the other is that the network can quickly converge to a stable and accurate consensus result. The proof of convergence theorem of distribution consensus is given in this paper. Lastly, the simulation results show the excellent characteristics of this new algorithm.
Citation: | HUANG Qing-dong, SUN Qing, YAN Qiao-qiao. Distributed Consensus Cooperative Spectrum Sensing Method Based on Connected-Dominating-Set[J]. Journal of University of Electronic Science and Technology of China, 2017, 46(5): 660-665. doi: 10.3969/j.issn.1001-0548.2017.05.004 |