中文摘要：

本文主要研究了人工噪声辅助的多输入单输出（Multiple-input Single-output,MISO）物理层安全传输系统中的最小反馈比特数问题。论文对信道方向信息采用基于随机矢量量化（Random Vector Quantization,RVQ）的码本反馈方法,首先定量分析了RVQ量化导致的系统保密速率损失,充分考虑不同发送信噪比条件与量化误差的特点,推导出了所需最小反馈比特数的闭合表达式。分析表明为保持恒定的遍历保密容量损失,反馈比特数应随对数信噪比及（Nt-1）线性变化（Nt为发送天线数）。理论分析和仿真结果表明,依据本文得到的闭合表达式调整反馈比特数,可以满足系统的安全性能要求。现有研究没有考虑信噪比较低的情况,而本文的结论适用于各种信噪比情况,对于人工噪声辅助的物理层安全传输策略实用化具有指导意义。

英文摘要：

In this paper, we studied on the minimum feedback bits number in multiple-input-single-output （MISO） systems with artificial noise assisted secure transmission. We used codebook to convey channel direction information quantized by random vector quantization （RVQ） method. We analyzed ergodic secrecy capacity loss quantitatively due to RVQ quantization considering different transmitted SNR and quantization error features. The closed-form of minimum feedback bits number was derived. To maintain a constant secrecy capacity loss, feedback bits should be sealed linearly with the logarithmic transmitted SNR as well as （Nt-1）（ Nt is the transmit antenna number）. Theoretical analysis and simulation results show that it satisfies security demands through adjusting feedback bits number according to our proposed closed form expression. Present research did not consider the case of low SNR. Our conclusion is suitable for all the SNR cases and makes contributions to the realization of artificial noise assisted physical secure transmission strategies.