切换天线发射的低截获率通信信号物理层安全传输  

Signal Transmitted from Switched Antenna Array with Low Interception Probability for Physical Layer Security

作　　者：洪涛[1] 宋茂忠[1] 刘渝[1] 

机构地区：[1]南京航空航天大学信息科学与技术学院,南京210016

出　　处：《应用科学学报》2011年第4期368-373,共6页Journal of Applied Sciences

基　　金：江苏省自然科学基金(No.BK2009367);航空基金(No.20095152026)资助

摘　　要：为了提高通信信号在无线传输过程中的物理层安全性,提出一种低截获率物理层安全通信信号.发射机根据接收机发送的训练符号估计信道,并随机选取信道质量较好的天线加权发射信号.各天线的权系数由天线的信道信息和通信双方约定使用的扩频序列决定.由于发射天线的快速切换,发射信号是一种与发射天线信道信息和扩频序列相关的空间扩频信号.期望接收机可采用与普通扩频信号接收机相同的方法解调接收信号,而窃听接收机由于信道的快速切换无法正常解调接收信号.仿真结果表明,相比于参考方法发射信号,该文提出的信号不仅具有相同的物理层防窃听能力,而且还具有防侦测和一定的抗干扰能力,是一种更好的基于多天线发射的物理层安全通信信号.A signal transmitted from a switched antenna array with low probability of interception is proposed to ensure information security in the physical layer transmission.The main idea is that the transmitter estimates channel information from a training sequence transmitted by the mobile terminal and randomly selects several antennas for fast switching transmission.Weighting coefficients of each antenna are calculated according to channel information and the spread-spectrum sequence.Therefore,the signal is a space-spread-spectrum signal associated with the spread-spectrum sequence and the channel information of each antenna. In this way,the desired receiver with a single antenna can demodulate the received signal as traditional spread-spectrum signals,while eavesdroppers cannot extract any useful information from the received signal even if eavesdroppers know the spread-spectrum sequence of the transmit signal because of the fast switching of the transmit antenna.Simulation results show that the signal has the same ability of anti-eavesdropping,and has anti-jamming capability with low probability of detection compared to a reference method.

关 键 词：切换天线阵 低截获概率 安全通信 物理层安全 

分 类 号：TN929.5[电子电信—通信与信息系统]