协作频谱共享网络中的安全性能分析

发布时间：2018-06-30 20:27

本文选题：协作通信 + 频谱共享　；参考：《郑州大学》2017年硕士论文

【摘要】：协作分集技术和频谱共享技术的联合应用能有效对抗多径衰落、提高频谱利用率从而缓解频谱资源短缺的矛盾,物理层安全技术可以提高无线通信网络的传输安全性。然而目前研究协作频谱共享技术的相关文献大都以信道容量最大化或者频谱共享策略为研究目标,没有考虑系统能效和安全传输问题;物理层安全方面文献大都以安全容量最优或者总发射功率最小为研究目标。但是,随着无线通信领域的迅速发展,人们希望数据传输地更快、更安全,能量利用效率和系统稳定性更高。因此,不同技术的综合应用成为时代的必然。基于此,本文对协作频谱共享机制下系统的安全能效和中断概率做了相关研究,具体内容包括:1.在本文所提协作频谱共享机制中,充当中继节点的认知用户发射端利用功率分配因子?和1-?将授权网络数据和认知网络数据叠加后转发给相应的目的接收端,同时,伪装成合法用户的窃听节点也接收到叠加信号。基于此机制,研究了中继节点采用译码转发协议时系统安全能效最优的功率分配算法。针对目标函数非凸问题,利用分式规划和DC(Difference of Convex functions)规划理论对原问题进行迭代求解。仿真结果表明,相比保密速率最大化优化目标,所提算法能获得更高的安全能效,但因保密速率和安全能效之间的折中,此时保密速率有一定损失。2.针对上述协作频谱共享机制,研究了中继节点采用放大转发协议、满足峰值功率和保密速率约束下,系统安全能效最优的功率分配算法。联合应用分式规划、罚函数、交替搜索和DC规划理论将原目标函数进行等效和逐层分解。仿真结果对比了所提算法与遍历算法的性能差距,并验证了所提算法的收敛性能。分析了节点位置变化对系统安全能效的影响,并验证了物理层安全通信网络中依然存在保密速率和安全能效的折中。3.考虑了授权网络以频谱共享机会作为诱饵窃听认知网络机密数据的情形。针对授权用户发射端作为窃听节点的情形,推导得出了中继节点采用译码转发和放大转发协议时,授权网络的中断概率和认知网络安全中断概率的表达式以及闭式解,分析了功率分配因子取值范围和对系统中断概率的影响并通过仿真结果进行验证。
[Abstract]:The joint application of cooperative diversity technology and spectrum sharing technology can effectively resist multipath fading, improve spectrum efficiency and alleviate the contradiction of spectrum resource shortage. Physical layer security technology can improve the transmission security of wireless communication network. However, most of the literatures on collaborative spectrum sharing are focused on the channel capacity maximization or spectrum sharing strategy, and do not consider the energy efficiency and secure transmission of the system. Most of the literatures on physical layer security aim at optimal safety capacity or minimum total transmission power. However, with the rapid development of wireless communication, data transmission is expected to be faster, more secure, more efficient and more stable. Therefore, the comprehensive application of different technologies has become an inevitable trend of the times. Based on this, this paper studies the security energy efficiency and interruption probability of the system under the cooperative spectrum sharing mechanism, including: 1. In the cooperative spectrum sharing mechanism proposed in this paper, the cognitive user transmitter which acts as the relay node uses the power allocation factor. And 1? The authorized network data and cognitive network data are superimposed and forwarded to the corresponding destination receiver. At the same time, the eavesdropping nodes disguised as legitimate users also receive the superposition signals. Based on this mechanism, the optimal power allocation algorithm for the system security energy efficiency when the relay node adopts the decoding and forwarding protocol is studied. For the non-convex problem of objective function, the original problem is solved iteratively by fractional programming and DC (difference of Convex functions) programming theory. The simulation results show that the proposed algorithm can achieve higher security energy efficiency than the maximization of the security rate. However, due to the compromise between the security rate and the security energy efficiency, the security rate has a certain loss of .2. Aiming at the cooperative spectrum sharing mechanism, an optimal power allocation algorithm for system security energy efficiency under peak power and secure rate constraints is studied. The relay node adopts amplification and forwarding protocol to satisfy the constraints of peak power and secure rate. By using fractional programming, penalty function, alternating search and DC programming theory, the original objective function is decomposed into different levels. Simulation results compare the performance gap between the proposed algorithm and the ergodic algorithm, and verify the convergence performance of the proposed algorithm. The influence of node location change on system security energy efficiency is analyzed, and the compromise between security rate and security energy efficiency is verified in the physical layer secure communication network. In this paper, we consider that authorized network uses spectrum sharing as bait to eavesdrop on classified data of cognitive network. In view of the situation that the authorized user transmitter acts as the eavesdropping node, the expressions and closed solutions of the outage probability and the cognitive network security interrupt probability of the relay node are derived when the relay node adopts the decoding, forwarding and amplifying forwarding protocols. The range of power allocation factor and its influence on the outage probability of the system are analyzed and verified by simulation results.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN92

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