基于人工干扰的物理层安全通信方法研究

发布时间：2018-03-25 03:08

本文选题：物理层安全　切入点：人工干扰　出处：《西安电子科技大学》2014年硕士论文

【摘要】：无线通信对现代人们的生活、工作和学习等方方面面产生日益巨大的影响,无线通信系统的两个基本问题是数据的可靠性和有效性,然而,数据在空间中以电磁波的形式传播,无线信道具有广播、衰落和易接入的基本特征,非法的窃听者试图获取正在进行传输的信息而不被发现,甚至网络中存在恶意的发送者或干扰者,试图降低期望接收者的信号,数据的可靠通信将会面临巨大的威胁。一直以来人们对物理层干扰策略有着很大兴趣,尤其是在军事网络中,数据传输的安全性一直由网络层基于密钥的加密技术来保证的,加密体制的高计算复杂度和复杂的密钥分配及管理问题,推动了物理层安全通信人工干扰技术的产生和发展。物理层安全主要是指存在非法窃听者的情况下,保证机密消息在无线媒质中能够安全可靠传输,而无需依赖于更高层的加密体制,物理层安全的基本原则是利用噪声固有的随机性和通信信道,在对手的计算资源不受限和已知网络参数情况下,来限制对手可获得的信息比特数,可达到的安全性以保密速率或保密容量精确量化。本文研究的是物理层安全通信方法中的一种,不需要产生密钥,发送者在发送有用信号的同时,利用一部分可用功率发送人工干扰信号,通过设计合理的发送预编码机制,只降低窃听者的信道,再考虑一些可获得的信道状态信息,达到安全通信。本文首先研究了单用户MIMO系统人工干扰的应用,介绍了lattice检测理论,将人工干扰信号的模值归一化到一个特定的值,强制干扰项位于窃听者检测区域的边界,提高窃听者的误码率,并克服了窃听端天线数目必须小于发射端天线数目的限制。本文提出一个基于干扰对齐的人工干扰安全通信方法,系统模型为多用户多窃听者MIMO干扰信道,发送者同时发送有用信号和人工干扰信号,通过设计合理的发送预编码机制,即有用信号的预编码矩阵满足干扰对齐,消除了用户间干扰,人工干扰预编码矩阵用于干扰窃听者,降低窃听者的信道质量,提高用户的保密速率。本文用Matlab仿真软件对以上两种方法分别进行了仿真,并对仿真结果进行了分析。
[Abstract]:Wireless communication has great influence on many aspects of modern people's life, work and study. The two basic problems of wireless communication system are the reliability and validity of data. However, the data is transmitted in the form of electromagnetic wave in space. The wireless channel has the basic characteristics of broadcast, fading and easy access, illegal eavesdroppers try to obtain the information being transmitted without being found, and even the malicious sender or jammer exists in the network, trying to reduce the signal of the intended receiver. The reliable communication of data will face a great threat. People have always been interested in the interference strategy of physical layer, especially in military network, the security of data transmission has always been guaranteed by the encryption technology based on key in the network layer. The high computational complexity and complex key distribution and management problems of encryption system promote the production and development of physical layer security communication artificial interference technology. Physical layer security mainly refers to the presence of illegal eavesdroppers. The basic principle of physical layer security is to make use of the inherent randomness of noise and communication channel to ensure that confidential messages can be transmitted safely and reliably in wireless media without relying on a higher level encryption system. To limit the number of bits of information available to the opponent if the computing resources of the opponent are not limited and the network parameters are known, The reachable security is quantized precisely at the rate or capacity of security. In this paper, we study one of the physical layer secure communication methods, which does not need to generate the key, and the sender sends the useful signal at the same time. A part of available power is used to transmit artificial interference signal. By designing reasonable transmission precoding mechanism, only the channel of eavesdropper is reduced, and some available channel state information is considered. In order to achieve secure communication, this paper first studies the application of artificial interference in single user MIMO system, introduces the theory of lattice detection, normalizes the module value of artificial interference signal to a specific value, and forces the interference term to be located at the boundary of eavesdropping detection area. In order to improve the bit error rate of eavesdroppers and overcome the limitation that the number of antennas at the eavesdropping end must be smaller than the number of antennas at the transmitter, a secure communication method based on interference alignment is proposed in this paper. The system model is multi-user multi-eavesdropping MIMO interference channel. The sender sends both useful signal and artificial interference signal. By designing a reasonable transmission precoding mechanism, the pre-coding matrix of the useful signal meets the interference alignment. The interference between users is eliminated, the artificial interference precoding matrix is used to interfere with eavesdroppers, the channel quality of eavesdroppers is reduced, and the security rate of users is improved. The simulation results are analyzed.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN918.4

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