多小区组播系统中物理层安全传输技术研究

发布时间：2018-05-19 08:36

本文选题：组播系统 + 物理层安全　；参考：《北京交通大学》2017年硕士论文

【摘要】：无线组播技术利用无线信道的广播特性,能够同时向不同的用户发送相同的数据,因而具有较高的通信效率,在移动通信系统中有着广泛的应用前景。但是无线信道的高度开放性也为组播系统的安全性带来了严峻的挑战。物理层安全技术从信息论角度出发,利用无线信道的传输特性以及信号处理技术,能够有效地提高系统安全性,是现有安全机制的一个重要补充。本文主要研究了多小区组播系统的安全传输问题,研究内容如下:首先,针对多小区组播系统中下行链路安全传输问题,本文提出了一种基于多个小区联合波束赋形的安全传输策略。通过结合半正定松弛技术和一维线性搜索方法,研究了服务质量(Quality of Service,QoS)和安全传输速率约束下的总发射功率最小化问题,并对各基站的波束赋形向量进行了联合优化。仿真结果表明,该算法能够有效地降低整个系统以及本地小区的功率消耗。其次,在上一章内容的基础上,研究了多个窃听用户场景下的多小区组播安全传输问题。该场景中,周边小区用户均被认为是潜在的窃听者。对于理想信道状态信息情况,首先对功率约束下的秘密速率最大化问题进行了研究。进一步,针对窃听信道状态信息存在误差场景,利用最差性能优化方法,设计了鲁棒性的安全传输策略。仿真结果表明,相比于独立波束赋形方法,本文提出的算法能够有效地提高系统的安全传输速率,并且鲁棒性发射策略依然可以获得较好的安全传输性能。
[Abstract]:Wireless multicast technology can transmit the same data to different users at the same time, so it has high communication efficiency and has a wide application prospect in mobile communication systems. However, the high openness of wireless channel also brings serious challenges to the security of multicast system. From the point of view of information theory, physical layer security technology can effectively improve system security by using wireless channel transmission characteristics and signal processing technology, which is an important supplement to existing security mechanisms. This paper mainly studies the secure transmission of multi-cell multicast system. The research contents are as follows: firstly, aiming at the downlink secure transmission in multi-cell multicast system, In this paper, a secure transmission strategy based on multiple cell joint beamforming is proposed. Combined with positive semidefinite relaxation technique and one-dimensional linear search method, the problem of minimizing total transmit power under the constraint of quality of Service (QoS) and secure transmission rate is studied, and the beamforming vectors of each base station are jointly optimized. Simulation results show that the proposed algorithm can effectively reduce the power consumption of the whole system and local cells. Secondly, on the basis of the previous chapter, the secure transmission of multi-cell multicast in multiple eavesdropping user scenarios is studied. In this scenario, the surrounding cell users are considered to be potential eavesdroppers. In the case of ideal channel state information, the problem of secret rate maximization under power constraints is studied. Furthermore, in view of the error scenario of eavesdropping channel state information, a robust secure transmission strategy is designed by using the worst performance optimization method. The simulation results show that compared with the independent beamforming method, the proposed algorithm can effectively improve the secure transmission rate of the system, and the robust transmission strategy can still achieve better secure transmission performance.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN918

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