全双工中继网络中的物理层安全技术研究

发布时间：2018-06-15 13:49

本文选题：物理层安全 + 协作通信　；参考：《电子科技大学》2017年硕士论文

【摘要】：由于无线通信的广播特性,通过无线介质传输的信息有可能受到非法用户截获和窃听。传统的信息安全方法一般基于网络层密钥技术,需要很强的计算机处理能力才能破译,随着计算机运算速度不断提高,被破解的可能性也大大提高。物理层安全技术通过无线信道的物理特征来确保通信信息的安全性,使无线通信系统中的传输数据在底层进行处理,可以增强传输过程中的数据保密性。随着全双工无线电通信技术的迅速发展,目前最新的研究实验成果已经实现信号同时同频传输,其自干扰可以被抑制到白噪声水平。在全双工中继场景下对物理层安全技术进行研究,既可以发挥协作中继的特点,又可以通过全双工技术使系统传输速率与安全保密性能近乎倍增,因此研究全双工协作中继场景下的物理层安全技术具有重要意义。本文通过对人工噪声与中继波束成形矢量的设计,实现了全双工中继场景下的安全传输方法,主要研究工作如下:1.本文在多节点协作的全双工中继网络模型下,设计了融合人工噪声的中继转发方案,提出了基于安全速率最大化与功率最小化准则的优化算法,并通过对KKT条件的推导,以及安全速率最大化问题和功率最小化问题之间的强对偶性,证明了算法的最优性。仿真结果表明本文所提出的安全传输方案,相比原有的波束成形技术在系统性能上有显著提升。2.由于实际场景中发送端已知的信道状态信息具有不确定性这一现状,本文对全双工中继场景中的鲁棒性安全传输方案进行了设计。在有界误差模型和统计误差模型下,通过S-procedure等方法将窃听端的SINR约束转换为线性不等式约束,将最大化合法用户端SINR的优化问题转化为凸优化问题,推导出使系统获得最大保密容量的波束成形矢量与人工噪声矩阵,从而使非完美信道场景中的通信安全性得到了保障。3.本文提出信源与中继相互协作,功率联合分配的安全传输方案。中继发送功率较高时,由于自干扰噪声等因素的影响,仅考虑中继之间互相协作难以使系统安全容量继续提高。本文在所设计中继转发方案的基础上做出改进,提出了源与中继联合功率分配的算法,使系统安全性能获得进一步提高。
[Abstract]:Due to the broadcast characteristics of wireless communication, information transmitted through wireless media may be intercepted and eavesdropped by illegal users. Traditional information security methods are generally based on the network layer key technology, which requires strong computer processing ability to be deciphered. With the computer computing speed increasing, the possibility of being cracked is also greatly increased. Physical layer security technology ensures the security of communication information through the physical characteristics of wireless channel, and makes the transmission data in wireless communication system handle in the bottom layer, which can enhance the data confidentiality in the transmission process. With the rapid development of full-duplex radio communication technology, the latest experimental results have realized simultaneous transmission of signals at the same frequency, and their self-interference can be suppressed to white noise level. Under the full duplex relay scenario, the physical layer security technology can be studied, which can not only give play to the characteristics of cooperative relay, but also make the transmission rate and security performance of the system nearly double through full-duplex technology. Therefore, it is of great significance to study the physical layer security technology in the full duplex cooperative relay scenario. Based on the design of artificial noise and beamforming vector, the secure transmission method of full duplex relay is realized in this paper. The main research work is as follows: 1. In this paper, based on the full duplex relay network model of multi-node cooperation, a relay forwarding scheme with artificial noise is designed, and an optimization algorithm based on the maximization of security rate and power minimization criterion is proposed, and the KKT condition is derived. And the strong duality between the secure rate maximization problem and the power minimization problem, the optimality of the algorithm is proved. The simulation results show that the proposed secure transmission scheme can significantly improve the system performance compared with the original beamforming technology. Due to the uncertainty of the channel state information known to the sender in the actual scene, the robust secure transmission scheme in the full-duplex relay scenario is designed in this paper. Under the bounded error model and statistical error model, the SINR constraint of eavesdropping end is transformed into a linear inequality constraint by S-procedure method, and the optimization problem of SINR at the maximization of legitimate client is transformed into a convex optimization problem. The beamforming vector and the artificial noise matrix are derived to obtain the maximum security capacity of the system, so that the communication security in the imperfect channel scenario is guaranteed. 3. In this paper, a secure transmission scheme based on cooperative power allocation between source and relay is proposed. When the transmission power of relay is high, it is difficult to improve the security capacity of the system only by considering the cooperation between relays due to the influence of self-interference noise and other factors. Based on the proposed relay forwarding scheme, an algorithm of joint power allocation between source and relay is proposed in this paper, which can improve the security performance of the system.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN918

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