Li, LixinHe, JiaoYang, Lie-LiangHan, ZhuPan, MiaoChen, WeiZhang, HuishengLi, Xu2020-05-112020-05-114/2/2019Copyright 2019 IEEE Access. Recommended citation:Li, Lixin, Jiao He, Lie-Liang Yang, Zhu Han, Miao Pan, Wei Chen, Huisheng Zhang, and Xu Li. "Spectral-and Energy-Efficiency of Multi-Pair Two-Way Massive MIMO Relay Systems Experiencing Channel Aging." IEEE Access 7 (2019): 46014-46032. DOI: 10.1109/ACCESS.2019.2908882. URL: https://ieeexplore.ieee.org/abstract/document/8679985. Reproduced in accordance with the original publisher's licensing terms and with permission from the author(s).https://hdl.handle.net/10657/6440In this paper, we demonstrate the impact of channel aging on the spectral- and energy-efficiency performance of the multi-pair two-way massive MIMO relay (MTW-MMR) systems, where massive antennas are deployed at the relay and the amplify-and-forward (AF) protocol is operated. By assuming the maximum-ratio combining/maximum-ratio transmission (MRC/MRT) or zero-forcing reception/ zero-forcing transmission (ZFR/ZFT) relaying processing, we analyze the spectral efficiency (SE) and energy efficiency (EE) of the MTW-MMR systems experiencing both imperfect channel estimation and channel aging based on the four proposed power-scaling schemes. Furthermore, we compare the performance of the full-duplex (FD)-assisted MTW-MMR systems with that of the half-duplex (HD)-assisted MTW-MMR systems, showing that the FD mode outperforms the HD mode with the interference level not exceeding -15 dB. Our studies show that channel aging may significantly degrade the achievable performance in terms of SE and EE. However, the inter-pair interference caused by the other user pairs and the self-interference can be effectively mitigated by the MRC/MRT processing or ZFR/ZFT processing at the relay.Massive MIMOtwo-way relayfull-duplexhalf-duplexchannel agingmaximum-ratio combining/maximum-ratio transmissionzero-forcing reception/zero-forcing transmissionspectral-efficiencyenergy-efficiencyArticle