基于低分辨率模数转换的全双工大规模MIMO中继系统频谱效率分析

为了降低由于大规模基站天线阵列模数转换(analog-to-digital converters, ADCs)所造成的巨大硬件损耗，同时有效地提高系统的能量和频谱效率，基于迫零传输/迫零接收(zero-forcing transmitting/ zero-forcing receiving, ZFT/ZFR)预处理方案，文章提出了低分辨率模数转换的多用户全双工大规模多入多出(massive multiple-input multiple-output, massive MIMO)中继系统，基站采用放大转发(amplify-and-forward, AF)协议，并对系统频谱效率进行了分析。文章首先获得了任一用户对频谱效率的闭式表达式，然后分别对三种不同功率缩放方案下系统的频谱效率进行了渐近分析。研究结果表明，当基站天线数量足够大时，三种不同的功率缩放方案对系统的环路干扰和量化误差有不同的影响，且当信源功率固定、基站的传输功率与发送天线数量成反比时，系统能够有效地抑制系统的环路干扰和量化误差，这对低分辨率全双工massive MIMO 中继系统的部署具有一定的指导意义。 

Specrum Efficiency Analysis for Full-Duplex Massive MIMO Relaying System with Low-Resolution ADCs

While employing massive multiple-input multiple-output (MIMO) can enhance the throughput of wireless communication systems, the energy consumption is increasing with the number of antennas at massive MIMO base stations, which is caused by the numerous analog-to-digital convertors (ADCs). In order to overcome this problem, this paper presents a novel multi-user full-duplex (FD) massive MIMO amplify-and-forward (AF) relaying system. In the proposed scheme, the low-resolution ADCs are employed at massive MIMO antenna array, and the zero-forcing transmitting/ zero-forcing receiving (ZFT/ZFR) processing schemes are used. For such relay systems, we first obtain the tractable closed-form of spectrum efficiency of each user pair. Then we present the asymptotic analyses of SE under three different power-scaling laws. It is found that, when the number of antennas grows to infinity, with different power-scaling scenarios, the systems have different ability to restrict the effect of loop interference and low-resolution ADCs. Specially, both the impact of loop-interference and quantizer error on achievable SE can be restricted effectively only under the power-scaling scenario where the relay’s transmit power is scaled down with the number of transmit antennas at relay while the one of sources is fixed. The promising result has a certain guiding significance to the design of full-duplex massive MIMO relaying system with low-resolution ADCs.