多天线RFID系统物理层安全优化方案的研究

摘要

近年来,射频识别( RFID)技术作为构建"物联网"的关键技术受到人们的关注,如何保证RFID系统的通信安全也成为一个重要的挑战.基于物理层层面,研究了一种多天线无源RFID通信系统的安全传输性能,采用人工干扰(AN)技术,提出两种不同的安全优化方案:基于"发送功率最小化"以及"合法接收端信干噪比最大化",并分别给出两类方案的特例"零空间方案",接着利用半正定松弛以及凸优化的数学方法对方案进行优化.仿真证明,采用AN的两类方案安全性能均优于无AN方案,并且达到节省功率以及提高合法用户接收信噪比的目的,对功率受限的RFID设备具有重要的意义.%In recent years, Radio Frequency Identification(RFID) serves as a critical technology of "Internet of things" and attracts tremendous attention, and how to guarantee its communication security has become a challenge. Based on the physical layer, this paper does some researches on security performance of a passive RFID system equipped with multiple antennas. The paper adopts the technique of Artificial Noise(AN) and puts forward two different safety optimization schemes called "power minimization scheme"and "Signal to Interference and Noise Ratio(SINR) maximization scheme", and two related "null space schemes" are proposed. Then using the mathematical method called semi-definite relaxation and convex optimization to optimize those schemes ,simulations proves that security performance of the schemes that adopt AN are better than that without using AN, and achieve the purpose of power saving and SINR maximizing as well. The works really make a great impact on the power limited and cost constrained RFID systems.