论文标题
通过空间多路复用来扭转MMWave网络中致密化的诅咒
Reversing the Curse of Densification in mmWave Networks Through Spatial Multiplexing
论文作者
论文摘要
无线网络的金标准是，吞吐量随访问点（AP）的密度线性增加。但是，这种线性吞吐量增益被暂停在5G MMWAVE网络中，这主要是由于MMWave频段的通信距离短和MMWave AP的密集部署。由于在干扰限制的方向上运行，由增加的MMWave AP产生的骨料干扰将逐渐成为网络性能瓶颈，从而导致吞吐量的饱和。在本文中，我们建议通过在APS处采用空间多路复用来克服MMWAVE网络的致密高原。为了研究空间多路复用对MMWave网络的影响，我们首先得出了覆盖率的概率，这是空间多路复用增益的函数。然后，固定速率编码方案用于提供网络吞吐量。我们还介绍了致密增益的概念，以捕获通过AP致密化实现的网络吞吐量的改进。我们的结果表明，如果没有AP的空间多路复用，当AP的密度变得足够大时，MMWave网络的吞吐量将达到平稳。但是，通过在AP处启用空间多路复用，MMWave网络可以随着AP的数量的增长而连续收获吞吐量增长。通过为MMWave网络的吞吐量得出上限，我们可以随着空间多路复用增益的增加来量化潜在的吞吐量改善。但是，我们的数值结果表明，固定速率编码方案无法探索这种潜在的吞吐量增益。然后，我们证明了在MMWave网络中部署多速率编码方案的必要性，尤其是当MMWave AP的空间多路复用增益很大时。
The gold standard of a wireless network is that the throughput increases linearly with the density of access points (APs). However, such a linear throughput gain is suspended in the 5G mmWave network mainly due to the short communication distances in mmWave bands and the dense deployments of mmWave APs. As being operated in the interference-limited regime, the aggregate interference resulted from the increasing mmWave APs will gradually become the network performance bottleneck, which leads to the saturation of the throughput. In this paper, we propose to overcome the densification plateau of a mmWave network by employing spatial multiplexing at APs. To study the effect of spatial multiplexing on mmWave networks, we first derive the coverage probability as a function of spatial multiplexing gain. The fixed-rate coding scheme is then used to provide the network throughput. We also introduce the concept of densification gain to capture the improvement in network throughput achieved through the AP densification. Our results indicate that without the spatial multiplexing at APs, the throughput of mmWave networks will reach the plateau when the density of APs becomes sufficiently large. By enabling the spatial multiplexing at APs, however, the mmWave network can continuously harvest the throughput gains as the number of APs grows. By deriving the upper bound for the throughput of mmWave networks, we quantify the potential throughput improvement as the spatial multiplexing gain increases. However, our numerical results show that such a potential throughput gain cannot be explored by the fixed-rate coding scheme. We then demonstrate the necessity for deploying the multi-rate coding scheme in mmWave networks, especially when the spatial multiplexing gain at mmWave APs is large.
