论文标题
速率分割的辅助大规模机器类型的通信
Rate-Splitting assisted Massive Machine-Type Communications in Cell-Free Massive MIMO
论文作者
论文摘要
这封信的重点是将速率分类的多访问（RSMA）与时间划分双链细胞的大型MIMO（多输入多输出）进行集成，以进行大规模的机器类型通信。由于设备的数量大量，它们的零星访问行为和有限的连贯间隔，我们采用随机访问策略，所有主动设备都利用相同的飞行员进行上行链路通道估计。这引起了高度的试验污染情景，这不可避免地会导致通道估计值。由RSMA朝着不完美的通道状态信息的鲁棒性激励，我们提出了一个新型的RSMA辅助下行链路传输框架，用于无细胞大规模的MIMO。根据公共和私人流的下行链路可实现的光谱效率，我们设计了一种启发式的通用预码器设计，并为拟议的RSMA辅助方案提出了一种新型的Max-Min功率控制方法。数值结果表明，RSMA有效地减轻了下行链路中试验污染的效果，并比常规无细胞的大型MIMO网络获得了显着的性能增长。
This letter focuses on integrating rate-splitting multiple-access (RSMA) with time-division-duplex Cell-free Massive MIMO (multiple-input multiple-output) for massive machine-type communications. Due to the large number of devices, their sporadic access behaviour and limited coherence interval, we assume a random access strategy with all active devices utilizing the same pilot for uplink channel estimation. This gives rise to a highly pilot-contaminated scenario, which inevitably deteriorates channel estimates. Motivated by the robustness of RSMA towards imperfect channel state information, we propose a novel RSMA-assisted downlink transmission framework for cell-free massive MIMO. On the basis of the downlink achievable spectral efficiency of the common and private streams, we devise a heuristic common precoder design and propose a novel max-min power control method for the proposed RSMA-assisted scheme. Numerical results show that RSMA effectively mitigates the effect of pilot contamination in the downlink and achieves a significant performance gain over a conventional cell-free massive MIMO network.
