论文标题
MM波杂种大型MIMO架构的有效代码域NOMA收发器
An Efficient Code-Domain NOMA Transceiver for mm-Wave Hybrid Massive MIMO Architectures
论文作者
论文摘要
大量的MIMO和非正交多访问（NOMA）是未来无线系统的关键方法，因为它们比传统系统具有许多优势。在大规模的MIMO系统中研究了功率域的NOMA方法，而对于这项研究的主题，对代码域NOMA和大量MIMO的整合几乎没有工作。我们提出了一个通用框架，该框架采用基于用户组的混合边界建筑，用于MM波大规模的MIMO系统，其中NOMA被视为组内过程。结果表明，可以直接调整稀疏代码多访问（SCMA）和多用户共享访问（MUSA）的经典接收器。此外，提出了一种新型的接收器架构，它是对上行链路Musa提出的改进。该接收器使Musa比SCMA比SCMA更易于上行链路传输，其复杂性较低。我们提供了可实现的信息率（AIR）作为绩效指标的下限。我们表明，代码域NOMA方案的表现优于传统方法，其射频链数非常有限，在该方法中，用户在空间上彼此接近。此外，我们在不同的代码长度和超载方案的上行链路传输方面提供了分析，以利用弹性结构的上行链路传输。
Massive MIMO and non-orthogonal multiple access (NOMA) are crucial methods for future wireless systems as they provide many advantages over conventional systems. Power-domain NOMA methods are investigated in massive MIMO systems, whereas there is little work on integration of code-domain NOMA and massive MIMO which is the subject of this study. We propose a general framework employing user-grouping based hybrid beamforming architecture for mm-wave massive MIMO systems where NOMA is considered as an intra-group process. It is shown that classical receivers of sparse code multiple access (SCMA) and multi-user shared access (MUSA) can be directly adapted. Additionally, a novel receiver architecture which is an improvement over classical one is proposed for uplink MUSA. This receiver makes MUSA preferable over SCMA for uplink transmission with lower complexity. We provide a lower bound on achievable information rate (AIR) as a performance measure. We show that code-domain NOMA schemes outperform conventional methods with very limited number of radio frequency (RF) chains where users are spatially close to each other. Furthermore, we provide an analysis in terms of bit-error rate and AIR under different code length and overloading scenarios for uplink transmission where flexible structure of MUSA is exploited.
