Massive MIMO (MaMIMO) has become an integral part of the 5G standard, and is envisioned to be further developed in beyond 5G networks. With a massive number of antennas at the base station (BS), MaMIMO is best equipped to cater prominent use cases of B5G networks such as enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC) and massive machine-type communications (mMTC) or combinations thereof. However, one of the critical challenges to this pursuit is the sporadic access behaviour of the massive number of devices in practical networks that inevitably leads to the conspicuous pilot contamination problem. Conventional linearly precoded physical layer strategies employed for downlink transmission in time division duplex (TDD) MaMIMO would incur a noticeable spectral efficiency (SE) loss in the presence of this pilot contamination. In this paper, we aim to integrate a robust multiple access and interference management strategy named rate-splitting multiple access (RSMA) with TDD MaMIMO for downlink transmission and investigate its SE performance. We propose a novel downlink transmission framework of RSMA in TDD MaMIMO, devise a precoder design strategy and power allocation schemes to maximize different network utility functions. Numerical results reveal that RSMA is significantly more robust to pilot contamination and always achieves a SE performance that is equal to or better than the conventional linearly precoded MaMIMO transmission strategy.

翻译：微型和微型企业已成为5G标准的一个组成部分,预计将在5G网络之外进一步开发5G网络。由于基站(BS)有大量天线,马米亚公司最有能力满足B5G网络的显著使用案例,如增强移动宽带(EMBBB)、超可靠的低纬度通信(URLLC)和大规模机械式通信(MMMTC)或其组合。然而,这一努力的关键挑战之一是实际网络中大量装置的零星存取行为,不可避免地导致显著的试点污染问题。传统线性预先编码的物理层战略用于在时间部门进行下行链路传输(TDD D),马米亚公司在这种试点污染的存在中将带来显著的光谱效率损失。在本文中,我们的目标是将称为分率前多的多重接入(RSMA)与TDD MaMIMIMO的多重接入整合,并调查其SE的运行情况。我们提议在TDM MaMIMO系统(RSMA)的新型下行联线性传输框架框架,即不断将一个比高级的高级设计前的SIMO(SB)网络设计结果大大地展示到SIMO)之前的系统。