时间反演联合接收端人工噪声的安全传输方案

针对时间反演(time reversal, TR)技术无法较好地解决聚焦区内非法用户窃听的问题,提出了一种TR技术联合接收端人工噪声的物理层安全传输方案。首先,利用时间反演技术的空时聚焦性提高合法用户接收端的信噪比(signal to noise ratio, SNR)。其次,通过在接收端加入人工噪声来干扰非法用户对合法用户保密信息的窃听,以聚焦区内外系统安全性能为基础,推导出保密信干噪比(signal to interference plus noise ratio, SINR)、可达保密速率和误码率(bit error rate, BER)的解析表达式。最后，通过仿真分析证明了所提方案能提高系统的SINR和可达保密速率,同时还能降低合法用户的BER，使系统拥有更好的安全性能。

Secure transmission scheme of time reversal combined with artificial noise at receiver

For the problem of illegal user's eavesdropping in focusing areas can not be well solved by time-reversal (TR) technology, a physical layer secure transmission scheme combined with the TR technology and artificial noise at the receiver is put forward. Firstly, the signal to noise ratio (SNR) of legitimate user is improved by the spatial-temporal focusing of the TR technology. Secondly, by adding artificial noise to the receiver to interfere with illegal user's eavesdropping on the confidential information of legitimate user. Based on the security performance of the system inside and outside the focusing areas, the analytical expressions of the confidential signal to interference plus noise ratio (SINR), the achievable rate of secrecy and the bit error rate (BER) are derived. Finally, simulation analysis show that the proposed scheme can improve the SINR and the achievable rate of secrecy, at the same time reduce the BER of legitimate user, which brings better system security performance.