Optimal Design of Secrecy Massive MIMO Amplify-and-Forward Relaying Systems With Double-Resolution ADCs Antenna Array
Optimal Design of Secrecy Massive MIMO Amplify-and-Forward Relaying Systems With Double-Resolution ADCs Antenna Array
复制标题
具有双分辨率 ADC 天线阵列的保密大规模 MIMO 放大转发中继系统的优化设计
DOI：
10.1109/access.2016.2633330
复制
发表时间：
2016-01-01
期刊：
影响因子：
3.9
通讯作者：
Zhu, Hongbo
中科院分区：
文献类型：
--
作者：
Jia, Xiangdong;Zhou, Meng;Zhu, Hongbo
针对保密受限的大规模多输入多输出（MIMO）中继系统，从中继天线数等系统参数的优化设计角度出发，提出了一种更实用的混合模数转换器（ADC）方案--双分辨率ADC方案。在提出的双分辨率ADC方案中，中继站的$M$天线被分为两部分，其中一部分包括<inline-formula><tex-math notation="LaTeX">$M {0}$</tex-math></inline-formula>天线和<inline-formula><tex-math notation="LaTeX">$</tex-math></inline-formula><inline-formula><tex-math notation="LaTeX">M {1}</tex-math></inline-formula>$天线，前者采用仅需5~12量化比特的中分辨率ADC，后者采用低分辨率ADC。从中继到目的地的传输暴露给被动窃听者。对于这样的大规模MIMO中继系统，我们首先推导出合法用户的总可实现遍历速率以及相应的保密中断率。然后，建立了合理的能量消耗模型，推导出保密能量效率（SEE），充分利用了源功率、ADC分辨率以及中低分辨率ADC天线数比对保密能量效率的影响。数值结果表明，用中分辨率ADC代替高分辨率ADC有利于改善系统SEE，而对总可达速率的影响很小。特别地，我们得到了三个主要的启示：1）存在一个最优的源功率值，在该值下SEE最优; 2）对于给定的<inline-formula><tex-math notation="LaTeX">$M_{0}：M_{1} $</tex-math></inline-formula>，中分辨率ADC的最优量化比特值是有界的，在该值下系统具有更高的SEE，也就是说，我们得到了中分辨率ADC的分辨率的上界; 3）中分辨率ADC的最优量化比特<inline-formula><tex-math notation="LaTeX">数$B_{0}$</tex-math></inline-formula>和<inline-formula><tex-math notation="LaTeX">$M_{0}：M_{1}$</tex-math></inline-formula>共同影响天线总数的最优值。特别地，虽然对于纯高分辨率ADC系统，总天线的最佳数量是100个左右，但是对于所提出的双分辨率ADC系统，总天线的最佳数量将达到500~700个。最优天线数随着<inline-formula><tex-math notation="LaTeX">$B {0} $</tex-math></inline-formula>和$<inline-formula><tex-math notation="LaTeX">M {0}：M {1} $</tex-math></inline-formula>的减小而增大，从而进一步提高了系统性能。
This paper focuses on a secrecy constrained massive multiple-input multiple-output (MIMO) relaying system in terms of the optimal design of system parameters such as the optimal total number of antennas at relay, where a more practical mixed analog-to-digital converters (ADCs) scheme, double-resolution ADCs scheme, is proposed. In the proposed double-resolution ADCs scheme, the total <inline-formula> <tex-math notation="LaTeX">$M$ </tex-math></inline-formula> antennas at relay are divided into two parts, one of which includes <inline-formula> <tex-math notation="LaTeX">$M_{0}$ </tex-math></inline-formula> antennas with medium-resolution ADCs only requiring 5~12 quantization bits and the remainder of which consists of <inline-formula> <tex-math notation="LaTeX">$M_{1}$ </tex-math></inline-formula> antennas with low-resolution ADCs. The transmission from relay to destinations is exposed to a passive eavesdropper. For such massive MIMO relaying systems, we first derive the total achievable ergodic rates of legitimate users as well as the corresponding secrecy outage rates. Then, a reasonable energy consumption model is modeled so that the secrecy energy efficiency (SEE) is derived, where the effect of the source power, the resolutions of ADCs, and the ratio of the antenna numbers with medium- and low-resolution ADCs are exploited perfectly. The presented numerical results show that replacing high-resolution ADCs with medium-resolution ADCs is beneficial for improving the system SEE while the effect on the total achievable rate is very small. Specially, three main insights are achieved: 1) there exists an optimal value of the source power at which the SEE is optimal; 2) with given ratio <inline-formula> <tex-math notation="LaTeX">$M_{0} :M_{1} $ </tex-math></inline-formula>, the optimal value of quantization bits of medium-resolution ADCs is upper-bounded, under which the system has higher SEE, that is to say, we obtain the upper bound of the resolution of the medium-resolution ADCs; and 3) the optimal number of the total antennas is impacted jointly by the number <inline-formula> <tex-math notation="LaTeX">$b_{0}$ </tex-math></inline-formula> of the quantization bits of medium-resolution ADCs and the ratio <inline-formula> <tex-math notation="LaTeX">$M_{0} :M_{1}$ </tex-math></inline-formula>. Specially, while the optimal number of the total antennas is 100 or so for the pure high-resolution ADCs systems, the one for the proposed double-resolution ADCs systems would up to 500~700. Moreover, the optimal antenna number is increasing with the decrease of <inline-formula> <tex-math notation="LaTeX">$b_{0} $ </tex-math></inline-formula> and the ratio <inline-formula> <tex-math notation="LaTeX">$M_{0} :M_{1} $ </tex-math></inline-formula> so that the system performance can be improved further.