混合ADCs大规模MIMO放大转发中继系统安全性能分析

为了改善大规模多输入多输出(multiple-input multiple-output,MIMO)中继系统的能量效率和安全性能,提出了基于混合模数转换器(analog-to-digital converters,ADC)的大规模MIMO放大转发中继系统,该系统的中继天线由独立的两部分构成,M0个天线配置中分辨率(5 ～ 12) ADCs和M1个天线配置1 bit低分辨率ADCs.该大规模MIMO放大转发中继系统,通过采用随机矩阵理论,首先获得系统总的安全中断速率,然后根据构建的能量消耗模型,获得系统的安全能量效率(secrecy energy efficiency,SEE).仿真分析表明,在基于混合ADCs的大规模MIMO中继系统中,用中等分辨率ADCs代替高分辨率ADCs不仅能保证系统的安全中断性能,同时还能有效地改善系统的SEE;且存在使系统SEE最大的信源最优发射功率;同时,中分辨率天线数M0和低分辨率天线数M1的比例也是影响系统性能的重要参数.

Secrecy performance analysis of massive MIMO amplify-and-forward relaying systems with mixed-ADCs

In order to improve the energy efficiency and secrecy performance of massive multiple-input multiple-output (MIMO) relaying systems,this paper proposes a novel massive MIMO amplify-and-forward (AF) relaying system where the mixed analog-to-digital converters (ADCs) scheme is employed.In proposed system,the total antennas at relay are divided into two independent parts,one of which includes Mo antennas with medium-resolution ADCs only requiring 5 ～ 12 quantization bits,the remainder of which consists of M1 antennas with 1-bit low-resolution ADCs.For the massive MIMO AF relaying system,by using the random matrix theory,the total secrecy outage rate is derived firstly.Then,based on modeled energy consumption model,the secrecy energy efficiency (SEE) is derived.The presented simulations and numerical results show that in the mixed-ADCs-based massive MIMO AF relaying system,it is reasonable to replace the high-resolution ADCs with medium-resolution ADCs.The novel scheme improves the system SEE greatly,but has limited effect on system's secrecy outage performance.For the effect of the transmission power of sources,the results show that there exists an optimal value of the source power at which the SEE is optimal.Besides this,the effect of the ratio of the antenna numbers Mo and M1 is investigated.