基于用户配合的全双工蜂窝系统保密传输方案

Full duplex secret transmission scheme based on user cooperation

全双工人工噪声机制在干扰功率持续增加时性能提升受限,并且损失了双工增益。针对上述2个问题,提出一种基于用户配合的全双工蜂窝系统保密传输方案,半双工的用户上行发送的同时,与其配合的用户可以进行下行发送。蜂窝基站使用全双工技术实现配合用户的干扰消除,并且采用部分功率发送人工噪声干扰窃听者。在此基础上以最大化系统保密速率为目标,设计下行用户期望信号矢量与人工噪声波束矢量;并且利用一维线性搜索获得最优功率配比。仿真结果表明,参考RS-ref方法和HD方法,所提方法能获得的系统保密速率呈线性增长,并且能够获得全双工增益。

Full-duplex artificial noise scheme can achieve a limited improvement while the interference power keeps increasing and the full-duplex gain is null. To solve these two problems, a full-duplex secure transmission scheme based on user cooperation was proposed, in which the full-duplex receiver used partial power to send artificial noise, and transmitted the downlink signal by the remaining power to the user who shared the same frequency. In order to maximize the system secrecy rate, the beam vector of the desired signal and the artificial noise were designed. Besides, the optimal power allocation factor was obtained by one-dimensional search simply. Simulation results show that compared with the RS-ref and HD methods, the proposed method can achieve an approximate linear growth in high power and can obtain the full-duplex gain.