一种基于时空编码的物理层安全算法

针对多天线窃听系统的物理层安全问题，提出一种基于时空编码的预编码算法。首先，合法接收者发送训练序列用于发送者估计主信道状态信息，而窃听信道的状态信息合法用户均未知；其次，发送者利用均匀信道分解的方法提取主信道状态信息的特征参数，生成发射端预编码矩阵和合法接收端均衡矩阵，收发联合加密处理提高物理层安全；最后，利用 Monte Carlo方法进行仿真实验，数值分析表明，该算法在窃听者天线数目增多时能够实现非负的保密容量，即使窃听信道质量较好时，窃听者的接收性能仍维持在很差的水平，误码率高达0.5。

A Method Based on Space-Time Code for Physical Layer Security

A precoding algorithm based on uniform channel decomposition is proposed to enhance physical layer security in multiple-input multiple-output multiple-antenna-eavesdropper ( MI-MOME) wiretap channels. Firstly,the pilot sequences sent by legitimate receiver are emloyed by the transmitter to estimate the main channel state information,and the channel state information of the eavesdropper is assumed to be unavailable at the legitimate users. Then,with the full main channel state information,the proposed algorithm is used to process the transmit signal and ob-tain the equalization matrix of legitimate receiver. Thus,the secure transmission can be achieved through the encryption of transceiver. Finally, our performance analysis is verified by Monte Carlo method. These show that our algorithms can achieve a non-negative secrecy capacity. Al-though the eavesdropper has a higher signal-to-noise ratio ( SNR) ,the bit error ratio ( BER) is still in a higher level reaching to 0 . 5 .