协作认知无线电网络中物理层安全问题研究

发布时间：2018-06-01 09:17

本文选题：协作认知无线电网络 + 物理层安全　；参考：《北京交通大学》2017年博士论文

【摘要】：认知无线电技术可望解决频谱资源利用率低下的问题,在过去数十年里得到了长足发展。协作认知无线电作为认知无线电技术和协作中继传输技术的结合,受到了全球学术界的广泛关注。在协作认知无线电网络中,初级用户租赁其频谱供次级用户使用,以期通过次级用户的协作传输提高网络性能。同其他无线通信网络一样,由于无线信道的广播特性,协作认知无线电网络面临着窃听威胁。现有的网络安全机制建立在网络层之上,以密钥加密的方式保证保密通信。然而,随着窃听者计算能力的提高,现有加密机制的安全性能受到了冲击。此外,由于协作认知无线电网络自组织、低复杂度、资源受限等网络特点,算法复杂度高的密钥加密方式所必须的密钥分配和密钥管理在该网络中难以部署实施。不同于密钥加密方式,处于物理层的安全通信技术,可以充分利用无线信道固有的时变、随机等特性,能够从信息论的角度带来额外的安全保障,是现有安全机制的重要补充。物理层安全拥有低复杂度、低能耗、无需密钥生成分配等优势,特别适合应用于协作认知无线电网络。然而,目前已有的物理层安全方案所针对的网络环境较为单一,在网络结构复杂的协作认知无线电网络中性能较差。同时,已有的物理层安全方案对于用户合作机制未进行深入研究,在协作认知无线电网络中的可推广性和可实现性存在不足。本文针对上述内容,对协作认知无线电网络中的物理层安全问题进行了深入详细的研究,主要内容包括:1.研究了协作认知无线电网络中基于协作干扰的物理层安全问题。考虑到网络中用户的协作特性,提出使用协作干扰技术的物理层安全方案,保证了网络中初级用户和次级用户通信的可靠性和安全性,具体而言:1)使用半定规划理论,结合迫零波束成形技术,推导得出了网络中各个节点的波束成形向量和解码向量;2)使用几何规划方法,在全局功率约束条件下,优化得出了网络节点功率分配向量,获得了安全容量的最优解;3)研究了干扰源多选问题,使用联盟博弈形成理论,根据合并-分裂规则和最大帕累托比较标准,提出了干扰源多选算法,得出了稳定收敛的干扰源联盟结构。2.研究了协作认知无线电网络中的干扰源-中继节点联合选择问题。认识到已有研究对于协作节点信道状态信息瞬时已知的假设过于理想,本文考虑了仅可获知协作节点信道状态信息统计分布的情况,提出了基于最优停止理论的干扰源-中继节点联合选择方案,具体而言:1)将干扰源-中继节点联合选择问题建模为最优停止问题,综合考虑网络安全容量和时间效率,设计了停止收益函数;2)推导得出了每步观测收益函数期望值,提出了最优停止准则,给出了基于最优停止理论的选择算法,并证明了算法的收敛性质;3)证明了最优观测序列的存在性,并使用动态规划推导得出了次级用户的最优观测序列,优化了方案的性能。3.研究了协作认知无线电网络中的干扰源激励问题。已有的研究假设协作节点无偿的花费能量发送干扰信号,对于干扰源的激励问题未予考虑。考虑到协作认知无线电网络中用户的个人理性,本文提出了使用能量收集技术的干扰源激励方案。此外,不同于已有研究,本文将窃听者信道状态信息已知的假设弱化为仅可获知窃听者部分信道状态信息,具体而言:1)根据信道不确定范数约束模型,使用鲁棒优化方法,优化设计了最坏情况下网络中各个节点的发送功率协方差矩阵,提高了网络安全性能;2)定义了干扰源能量收集-协作干扰的协助模式,使用能量收集技术,达到了干扰源能量消耗的收支平衡;3)提出了基于维克里拍卖的干扰源激励算法,设计了合理的拍卖定价策略,得出了算法的最优策略均衡解,证明了算法满足用户诚实性和用户个人理性的性质,在保证初级用户安全性能的同时,有效的对次级用户进行了激励。
[Abstract]:Cognitive radio (cognitive radio) is expected to solve the problem of low utilization of spectral resources, which has made great progress in the past few decades. As a combination of cognitive radio and cooperative relay transmission, cooperative cognitive radio has attracted wide attention from the global academia. For secondary users, it is expected to improve network performance through the cooperative transmission of secondary users. Like other wireless communication networks, cooperative cognitive radio networks are faced with the threat of eavesdropping due to radio channel broadcasting characteristics. Existing network security mechanisms are based on the network layer to secure secure communication by key encryption. However, With the improvement of the ability of the eavesdropper, the security performance of the existing encryption mechanism has been impacted. In addition, the key distribution and key management of the key encryption method with high complexity are difficult to deploy in the network because of the self organization, low complexity and resource limited network characteristics of the cooperative cognitive radio network. The key encryption method, the secure communication technology in the physical layer, can make full use of the inherent time-varying and random characteristics of the wireless channel. It can bring additional security guarantee from the angle of information theory. It is an important supplement to the existing security mechanism. The physical layer has the advantages of low complexity, low energy consumption, and no key generation and distribution. It should be used for cooperative cognitive radio networks. However, the existing physical layer security schemes have a relatively single network environment, and the neutral ability of the cooperative cognitive radio networks with complex network structures is poor. At the same time, the existing physical layer security schemes do not study the user cooperation mechanism deeply and cooperate to recognize the wireless network. In this paper, the problems of physical layer security in cooperative cognitive radio networks are studied in detail in this paper. The main contents are as follows: 1. the problem of physical layer security based on Cooperative interference in cooperative cognitive radio networks is studied. Characteristics, a physical layer security scheme using cooperative interference technology is proposed to ensure the reliability and security of communication between primary users and secondary users in the network. In particular: 1) using the semidefinite programming theory, combining with zero forcing beam forming technology, the beamforming vector and decoding vector of each node in the network are derived, and 2) the use of geometric rules is used. Under the condition of global power constraints, the network node power distribution vector is optimized and the optimal solution of the security capacity is obtained. 3) the interference source multi selection problem is studied. The alliance game formation theory is used. According to the merger split rule and the maximum Pareto comparison standard, the interference source multi selection algorithm is proposed, and the stable convergence is obtained. The interference source alliance structure.2. studies the interference source relay joint joint selection problem in cooperative cognitive radio networks. It is realized that the assumption that the channel state information is known instantaneously in the cooperative node is too ideal. This paper considers the state information distribution of the channel state information which can only be known, and proposes the optimal stop. The interference source relay joint joint selection scheme of the stop theory, specifically: 1) modeling the joint selection problem of the interference source relay node as the optimal stopping problem, considering the network security capacity and time efficiency, designed the stop return function; 2) derives the expected value of the revenue function of each step, and puts forward the optimal stopping criterion. The selection algorithm based on optimal stopping theory is presented and the convergence property of the algorithm is proved. 3) the existence of the optimal observation sequence is proved, and the optimal observation sequence of secondary users is derived by using dynamic programming, and the performance.3. of the scheme is optimized to study the problem of interference source in the cooperative cognitive wireless network. In this paper, a interference source incentive scheme using energy collection technology is proposed in this paper. In addition, the channel state information of the eavesdropper is known in this paper. The assumption that the weakening is only partially informed of the partial channel state information of the eavesdropper, specifically: 1) based on the uncertain norm constraint model of the channel, using the robust optimization method, the transmission power covariance matrix of each node in the worst case is optimized, and the network security performance is improved; 2) the interference source energy collection - cooperative interference is defined. Assist mode, using energy collection technology to achieve the balance of energy consumption of interference sources; 3) a reasonable auction pricing strategy is designed based on the interference source incentive algorithm of Vicky auction, and the optimal strategy equilibrium solution is obtained. It proves that the algorithm satisfies the user honesty and the nature of the user's personal rationality. At the same time, the user's security performance is effectively stimulated by the secondary users.
【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TN925

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