基于窃听信道模型的保密传输设计与性能分析

发布时间：2018-03-11 00:15

本文选题：窃听信道模型　切入点：物理层安全　出处：《郑州大学》2017年硕士论文　论文类型：学位论文

【摘要】：无线通信系统具有开放性,随着通信业务逐渐丰富,信息安全事故频繁发生。计算机性能在不断提升,导致依赖于计算量和复杂度的上层安全措施越来越不可靠。于是,近年来物理层安全成为一个研究热点,其本质思想是利用无线信道的特性设计编码方案,使窃听者无法获取物理层信息。MIMO技术被引入以增强物理层安全,以往关于保密性能的分析中,通常假设天线对之间的子信道相互独立,这个前提条件不符合实际应用情况。此外,在发送端,传统的最优TAS方案在服务多用户方面存在不足,并且天线利用率较低。本文基于窃听信道模型,研究了传输系统的保密性能,工作如下:1.介绍了窃听信道模型,阐述了物理层安全的研究现状。介绍了MIMO技术,解释了天线相关性的成因。讲述了利用特征函数法得到接收信噪比的统计分布。2.设计了SIMO保密传输系统,假设信道衰落服从Nakagami-m分布,考虑接收天线相关性,研究了MRC接收机输出信噪比的统计特性,借此分析了系统保密性能。MATLAB蒙特卡洛仿真结果表明:(1)保密中断概率的解析表达式精确可靠;(2)当主信道的平均信噪比较大时,保密性能随天线相关性的增大而降低;(3)当主信道的平均信噪比较小时,情况与(2)相反;(4)增加接收天线的数目可提升保密性能。3.依据次序统计原理提出了qth TAS方案,设计了MIMO保密传输系统,推导了qth TAS/co-MRC方案下接收信噪比的概率密度函数表达式,借此分析了系统保密性能。蒙特卡洛仿真结果表明:(1)qth TAS方案能为用户提供不同等级的保密性能;(2)保密性能随发送天线数目的增加而提升。
[Abstract]:Wireless communication system is open, with the gradual enrichment of communication services, information security accidents occur frequently. The computer performance is constantly improving, resulting in more and more unreliable upper layer security measures, which rely on computational complexity and complexity. In recent years, physical layer security has become a research hotspot. Its essential idea is to design a coding scheme based on the characteristics of wireless channel, so that eavesdroppers can not obtain physical layer information. MIMO technology is introduced to enhance physical layer security. In the previous analysis of security performance, it is usually assumed that the subchannels between antenna pairs are independent of each other, which does not accord with the practical application. In addition, at the transmitter, the traditional optimal TAS scheme has shortcomings in serving multiple users. Based on the eavesdropping channel model, the security performance of transmission system is studied in this paper. The work is as follows: 1. The eavesdropping channel model is introduced, and the research status of physical layer security is described. The MIMO technology is introduced. The causes of antenna correlation are explained. The statistical distribution of receiving SNR is obtained by using the eigenfunction method. 2. The SIMO secure transmission system is designed. Assuming that the channel fading is distributed from Nakagami-m, the correlation of receiving antenna is considered. The statistical characteristics of the output signal-to-noise ratio (SNR) of the MRC receiver are studied. The simulation results of the system security. The Monte Carlo simulation results show that the analytical expression of the security interrupt probability of the MRC receiver is accurate and reliable when the average signal-to-noise ratio of the primary channel is high. The security performance decreases with the increase of antenna correlation. When the average SNR of the primary channel is small, the situation is opposite to that of No.2) the security performance can be improved by increasing the number of receiving antennas. According to the principle of order statistics, the scheme of qth TAS is proposed. The MIMO secure transmission system is designed, and the expression of probability density function for receiving signal-to-noise ratio under qth TAS/co-MRC scheme is derived. The Monte Carlo simulation results show that the TAS scheme can provide users with different levels of security performance and the security performance increases with the increase of the number of transmit antennas.
【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】：TN918

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