Since the introduction of fifth-generation new radio (5G-NR) in Third Generation Partnership Project (3GPP) Release 15, swift progress has been made to evolve 5G with 3GPP Release 18 emerging. A critical aspect is the design of massive multiple-input multiple-output (MIMO) technology. In this line, this paper makes several important contributions: We provide a comprehensive overview of the evolution of standardized massive MIMO features from 3GPP Release 15 to 17 for both time/frequency-division duplex operation across bands FR-1 and FR-2. We analyze the progress on channel state information (CSI) frameworks, beam management frameworks and present enhancements for uplink CSI. We shed light on emerging 3GPP Release 18 problems requiring imminent attention. These include advanced codebook design and sounding reference signal design for coherent joint transmission (CJT) with multiple transmission/reception points (multi- TRPs). We discuss advancements in uplink demodulation reference signal design, enhancements for mobility to provide accurate CSI estimates, and unified transmission configuration indicator framework tailored for FR-2 bands. For each concept, we provide system level simulation results to highlight their performance benefits. Via field trials in an outdoor environment at Shanghai Jiaotong University, we demonstrate the gains of multi-TRP CJT relative to single TRP at 3.7 GHz.
翻译:自在第三代伙伴关系项目(GPP)第15版中引入第五代新无线电(5G-NR)以来,在5G(5G)和3GP第18版中出现了3GP第18版方面迅速取得进展,一个关键方面是设计大规模多投入多产出(MIMO)技术。在这一行中,本文件作出了若干重要贡献:我们全面概述了3GPP第15至17版中大规模IMO标准化特征的演变情况,用于FR-1和FR-2两个波段之间的时间/频率外视双面操作。我们分析了频道国家信息框架、波纹管理框架和目前连接CSI的增强情况。我们介绍了3GPP第18版中新出现的需要立即注意的问题,其中包括高级代码设计和为具有多个传输/接收点的一致联合传输(CJT)声调参考信号设计。我们讨论了在调试参考信号设计、增强移动能力以提供准确的CSI估计数和为FRF-2波段设计的统一传输配置指标框架的进展。我们在每个概念上提供系统级模拟结果,以突出TRPM的实地试验结果。