摘要
为了保障时间反演正交频分复(Time reversal-orthogonal frequency division multiplex,TR-OFDM)系统的物理层安全传输,提出了一种基于四元数加密的安全传输算法。该算法主要分为3个步骤:发射端和合法接收端利用估计信道得到加密传输过程中需要的四元数,即密钥;发射端将需要传输的比特序列做三维映射,利用四元数对三维星座点做旋转加密,调制为OFDM符号并经过时间反演处理之后发射出去;合法用户利用四元数进行解密和解调,从而获得传输的数据,而窃听者因为不知道密钥而无法获得传输信息。因此所提算法保证了系统数据传输的安全性。通过仿真证明本文所提出算法可以使窃听用户的误符号率始终保持在0.5左右;在相同信噪比下,较传统的二维调制,合法用户可以实现更低的误符号率;相较于人工噪声技术方案,本文所提算法不会影响合法用户的误符号率。
In order to ensure the safe transmission of the time reversal-orthogonal frequency division multiplex(TR-OFDM)system,this paper proposes a secure transmission algorithm based on quaternion encryption. The scheme is mainly divided into three steps. In the first step,the transmitter and the legitimate receiver use the estimated channel to obtain the quaternion required in the process of encrypted transmission,that is,the key. In the second step,the transmitting end takes the bit sequence to be transmitted three-dimensional mapping, then uses the quaternion to rotate and encrypt the three-dimensional constellation points,and finally modulates them into OFDM symbols and transmits them after time inversion processing. In the third step,the legitimate user uses the quaternion to decrypt and demodulate to obtain the transmitted data. The eavesdropper cannot obtain the transmission information because they do not know the key. Therefore,the proposed scheme ensures the security of system data transmission. The simulation results show that the proposed algorithm can keep the bit error rate of eavesdropping users at about 0.5. Under the same SNR,legal users can achieve a lower bit error rate than traditional two-dimensional modulation. Compared with the artificial noise scheme,the proposed algorithm will not affect the bit error rate of legitimate users.
作者
陈善学
杜文正
冯叶青
李方伟
CHEN Shanxue;DU Wenzheng;FENG Yeqing;LI Fangwei(College of Communication and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China)
出处
《数据采集与处理》
CSCD
北大核心
2021年第6期1197-1204,共8页
Journal of Data Acquisition and Processing
基金
国家自然科学基金(61771084)资助项目。
关键词
时间反演
正交频分复用
三维星座旋转
四元数
time inversion
orthogonal frequency division multiplexing
three-dimensional constellation rotation
quaternion
