混合双工主动窃听系统中的干扰端优化研究

随着不法分子对公共安全的威胁日益加大，主动窃听在商业和军事领域开始发挥重要作用。针对可能存在的解码转发中继网络下的可疑通信，提出了一种混合双工主动窃听系统。假设可疑用户受到干扰后，为了保持恒定的中断概率，将被迫改变可疑发送者的发送速率，利用这一特性对主动窃听者干扰端进行优化处理使得平均窃听速率最大化。通过将窃听到的两个时隙的信息进行不同的处理，分析了接收端两种不同信号合并方案下的平均窃听速率以及相应的最优干扰功率，最后还比较了最优干扰策略下该系统与其他文献中的系统的窃听性能差异。表达式和仿真结果表明，同样在最优干扰策略下，本文提出的混合双工主动窃听系统在接收端采用最大比合并方案时的主动窃听性能最优。 

Research on Jamming Optimization in Hybrid Duplex Proactive Eavesdropping System

As the threat from criminals to public safety is increasing, proactive eavesdropping begins to play an important role in the field of commercial and military. In view of this suspicious communication with decode-and-forward relay network, a proactive eavesdropping system of hybrid duplex is proposed. Assuming that when the suspicious receiver is disturbed, the transmission rate of the suspicious sender is forced to change in order to maintain a constant outage probability. Take advantage of this, the interference terminal of proactive eavesdropping is optimized to maximize the average eavesdropping rates. And besides, the average eavesdropping rate and the optimal jamming power under two different signal combination schemes at the eavesdropping receiver are analyzed. Finally, the eavesdropping performance of the system under the optimal jamming strategy is compared with that of other systems in the reference. The expression and simulation results show that, under the same optimal jamming strategy, the hybrid duplex proactive eavesdropping system proposed in this paper has the best proactive eavesdropping performance when the receiver adopts the maximum-ratio combined scheme.