基于数学模型的无线通信系统窃密保护方法研究

蔡敏

摘  要： 目前研究的无线通信系统窃密保护方法多是在有线通信基础上研发的，有效性差，保密能力不好。为此，利用人工噪声干扰技术和信息加权技术建立一个新的统一的数学模型。在物理层上设置密钥和人工噪声，通过在合法用户上传递保密信息，非法用户上加入人工干扰降低窃听端的信噪比。为降低发射天线端的个数限制，利用有限码集特性在窃听端引入盲符号，实现无线通信系统窃密保护。为检测方法的有效性，设定对比实验，结果表明，在引入基于数学模型的无线通信系统窃密保护方法后，信道的保密容量平均增加0.2 bit·s-1·Hz-1，用户的安全性可以得到有效保障。

关键词： 无线通信系统; 信息保密; 窃密保护; 数学模型; 人工噪声干扰; 信息加权

中图分类号： TN918?34                            文献标识码： A                       文章编号： 1004?373X（2020）03?0018?04

Research on wireless communication system eavesdropping

protection method based on mathematical model

CAI Min

（School of Mathematics and Physical Science， Xuzhou University of Technology， Xuzhou 221008， China）

Abstract： At present， most of the eavesdropping protection methods of wireless communication system are developed on the basis of wire communication， which has poor effectiveness and confidentiality. In view of this， a new unified mathematical model is created with the artificial noise jamming technology and the information weighting technology. As far as the model is concerned， the secret key and artificial noise are set in the physical layer， the confidential information is transmitted for valid users and the artificial interference is implemented for invalid users to reduce the signal?to?noise ratio of eavesdropping terminal. In order to reduce the number limitation at the transmitting antenna terminals， blind symbols are introduced into eavesdropping terminal according to the characteristics of the limited code set to realize the eavesdropping protection of wireless communication system. Comparative experiments were set up to verify the validity of the method. The results show that the channel confidential capacity is increased by 0.2 bit·s-1·Hz-1 on average after introducing the wireless communication system eavesdropping protection method based on mathematical model， and the user security can be effectively guaranteed.

Keywords： wireless communication system; information confidentiality; eavesdropping protection; mathematical model; artificial noise jamming; information weighting

0  引  言

在無线通信系统中，信道具有一定的开放性，信息在传输过程中，安全性难以保障，当信息被不合法的用户获取后，就会带来安全危害[1]。目前研究的解决无线通信系统窃密方法大多数都是源于有线通信系统中的窃密方法，例如，在高层设定密钥加密信息源，设定用户认证，这种完全照搬的方法对通信双方的密钥要求极高[2]。除此之外，相关学者还设定了跳扩频技术，跳扩频技术虽然具有较高的安全性，但是接收方必须要具备预知跳扩频的能力。无论是密钥保护法，还是跳扩频信息序列保护法，一旦出现信息泄露，上述的保密通信方法就会完全失效[3]。……