基于物理层安全的无线携能中继系统性能分析和优化

发布时间：2018-08-13 11:02

【摘要】：由于电磁波在自由空间传输的广播特性,无线通信不可避免地受到非法窃听的威胁。传统意义上,信息安全一般通过高层的加密机制来实现。近年来,物理层安全作为一种前景广阔的信息安全技术,受到了学术界和工业界的广泛关注。物理层安全技术利用无线信道本身的随机特性,如衰落、噪声和干扰等,使得窃听节点无法正确译码所截获的信号,从而保证信息传输的安全性。本文考虑一个大规模多天线携能中继系统,其中源节点在中继节点的协助下向目的节点传输保密信息,而一个非法的窃听节点企图窃取来自中继节点的转发信息。中继节点能量受限,源节点向中继节点同时传输信息和能量,而中继节点利用接收到的能量对信息进行转发。首先,在中继节点只能获取不完整合法信道状态信息和无法获取窃听信道状态信息的情况下,文章分析了在采用放大转发(AF)和解码转发(DF)两种协议下的大规模多天线携能中继系统的安全中断容量。进一步,对两种中继协议下的安全中断容量进行了渐近分析,得到了系统的极限性能。为了提升系统的安全性能,提出了安全中断容量最大化功率分配方案和中继转发协议切换方案。其次,为了同时从安全性和资源利用的有效性两个方面分析系统性能,建立了中继系统的总功率消耗模型,并给出了AF无线携能中继系统的安全能量效率表达式。以最大化安全能量效率为目标,对源节点的发射功率进行优化,给出了安全能量效率最大化功率分配算法。仿真结果证明了所提出的功率分配算法的有效性。最后,考虑到绿色通信的要求,研究了自由空间路径损耗模型下的功率消耗,并得到了DF携能中继系统安全能量效率闭式表达式。通过设计源节点发射功率分配方案,实现了系统安全能量效率的最大化。数值仿真验证了所提出的功率分配方案的有效性,并对比了系统在不同参数取值下的性能。
[Abstract]:Due to the broadcast characteristics of electromagnetic wave transmission in free space, wireless communication is inevitably threatened by illegal eavesdropping. In the traditional sense, information security is generally realized by high-level encryption mechanism. In recent years, physical layer security, as a promising information security technology, has received extensive attention from academia and industry. Physical layer security technology makes use of the random characteristics of the wireless channel such as fading noise and interference to make the eavesdropping node unable to decode the intercepted signals correctly so as to ensure the security of information transmission. In this paper we consider a large scale multi-antenna portable relay system in which the source node transmits confidential information to the destination node with the assistance of the relay node while an illegal eavesdropping node attempts to steal the forwarding information from the relay node. The energy of the relay node is limited, the source node transmits the information and energy to the relay node simultaneously, and the relay node transmits the information using the received energy. First, if the relay node can only obtain incomplete legitimate channel state information and eavesdropping channel state information, In this paper, the security interrupt capacity of large scale multi-antenna portable relay system is analyzed under the two protocols of amplifying and forwarding (AF) and decoding forwarding (DF). Furthermore, the security interrupt capacity under two relay protocols is asymptotically analyzed, and the limit performance of the system is obtained. In order to improve the security performance of the system, a security interrupt capacity maximization power allocation scheme and a relay forwarding protocol switching scheme are proposed. Secondly, in order to analyze the system performance both in terms of security and efficiency of resource utilization, the total power consumption model of the relay system is established, and the expression of the secure energy efficiency of the AF wireless portable relay system is given. In order to maximize the safety energy efficiency, the transmission power of the source node is optimized, and the maximum power allocation algorithm of the safety energy efficiency is presented. Simulation results show the effectiveness of the proposed power allocation algorithm. Finally, considering the requirements of green communication, the power consumption under the free space path loss model is studied, and the closed expression of secure energy efficiency of DF power relay system is obtained. The system safety energy efficiency is maximized by designing the source node transmission power allocation scheme. The effectiveness of the proposed power allocation scheme is verified by numerical simulation, and the performance of the system under different parameters is compared.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN92

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