基于多节点协作的高鲁棒性低度复杂的抗窃听技术研究

This project focuses on the physical-layer security issues of wireless communication systems and investigates how to improve the system performance against eavesdropping by fully utilizing the cooperative techniques. Focusing on wireless eavesdropping network, multi-node cooperation features on anti-eavesdropping are fully exploited. And further, this project integrates the theories of graph theory, stochastic process, optimization method and other related theories, and considers two associated problems: a) how to design robust and low complexity anti-eavesdropping techniques by employing multi-node cooperation in order to improve system physical-layer security? b) how to evaluate whether an anti-eavesdropping technology to meet the demand and make a reasonable choice to select a suitable anti-eavesdropping policy? That is, multi-node cooperative relaying based anti-eavesdropping strategy designs, multi-node cooperative jamming based anti-eavesdropping strategy designs, anti-eavesdropping performance evaluation and strategy selection. Innovation point of our project lies in taking full advantage of cross-disciplinary research theory to solve the problem. This project pioneers to apply graph theory firstly to transform the multi-node cooperative relaying anti-eavesdropping designs into the shortest path search problem of graph theory. The completion of this project can provide valuable theoretical basis and technological support for establishing a safe and reliable wireless network. With broad application prospect, this project can help to propose key proposals with independent intellectual property rights in the relevant standardization process.

本课题围绕无线通信系统的物理层安全问题，研究如何充分利用协作技术，提高系统的抗窃听性能。课题重点针对无线窃听网络，充分利用多节点协作的特性，并进一步融合图论、随机过程、最优化方法等相关理论，解决两个相关问题：一是如何通过多节点协作的方法，设计高鲁棒性、低实现复杂度的抗窃听方案，提升系统的抗窃听能力？二是如何评价一种抗窃听技术是否满足需求，及选择合适的抗窃听策略？即多节点协作中继抗窃听策略研究、多节点协作干扰抗窃听策略研究、抗窃听性能评估及策略选择三方面主要研究内容。课题的创新点在于充分利用交叉学科理论解决研究问题，首次运用图论相关理论，开创性地将基于协作中继的抗窃听设计巧妙地转化为图论的最短路搜索问题。课题的完成可以为建立安全可靠的无线网络提供理论依据和技术支撑，应用前景广阔，并有助于在相关标准化进程中提出具备自主知识产权的关键技术提案。

由于无线信道的开放性和物理层的广播特性，使得物理层安全问题日益突出。本项目围绕无线通信系统的物理层安全问题，研究如何充分利用协作技术，提高系统的抗窃听性能，解决两个相关问题：一是如何通过多节点协作的方法，设计高鲁棒性、低实现复杂度的抗窃听方案，提升系统的抗窃听能力？二是如何评价一种抗窃听技术是否满足需求，及选择合适的抗窃听策略？围绕这两个问题，本项目完成了多节点协作中继抗窃听策略研究、多节点协作干扰抗窃听策略研究、抗窃听性能评估及策略选择三方面的研究内容。标志性成果有：1）提出了一种基于双向中继传输技术的机会协作中继抗窃听方法和一种基于图论的多跳协作中继抗窃听方法，分别解决了对窃听节点信道信息的依赖问题和无线网络拓扑结构到图模型的转换问题。2）提出了一种基于全双工技术的半干扰协作方法，解决了协作干扰同样会降低合法链路的信道容量的问题，实现了集协作干扰和协作中继于一体的协作模式，有效对抗窃听者，提高系统的物理层安全。3）提出了一种权衡安全性可靠性的功率分配方法，通过将总功率拆分为传输和干扰两部分有效解决了多目标优化问题，实现了通过调整一个权衡因子就可以完成权衡的操作，提高了系统的权衡安全性和可靠性。