The potential of a system combining millimeter- wave (mmWave) communication and multiple- input multiple-output (MIMO) technology has motivated an extensive effort in both the research community and industry. With the much higher spectrum band, mmWave is considered to be a promising technology to solve the congestion problem in the sub-6 GHz band for future massive Internet of Things (IoT) systems. However, mmWave is still a long way from being a practical implementation for an IoT terminal due to high hardware cost and energy consumption. In this article, we introduce a new mmWave transmission technology called wireless beam modulation (WBM). The distinguishing feature of WBM is that bit information is transmitted through the propagation attenuation differences of signal beams instead of being carried by the original signal beam. While maintaining the high data transmission capability of mmWave frequencies, this change brings the advantage of high energy efficiency and low-cost mmWave hardware implementation to the IoT node. It can be deployed without shifter array and complex signal processing, such as precoding or even channel estimation. The basic idea of WBM is based on the recently proposed over-the-air modulation (OTAM) method but with several significant improvements. By formulating multiple beams at the access point (AP) node, WBM enables multiple- user access with spatial-division multiplexing, which significantly improves the spectrum efficiency compared to OTAM. Moreover, by aligning multiple beams between the IoT nodes and the central AP, WBM provides robust transmission and allows higher-order modulation. Hence, the proposed WBM achieves a good balance between high data transmission and spectrum efficiency with low hardware cost, which is promising for upcoming mmWave massive IoT systems.

中文翻译：

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无线波束调制：适用于未来大规模物联网系统的节能和频谱高效通信技术

结合毫米波（mmWave）通信和多输入多输出（MIMO）技术的系统的潜力激发了研究界和业界的广泛努力。随着更高的频段，mmWave被认为是解决未来大规模物联网（IoT）系统低于6 GHz频段拥塞问题的有前途的技术。但是，由于高昂的硬件成本和能耗，mmWave距离物联网终端的实际实现还有很长的路要走。在本文中，我们介绍了一种称为无线波束调制（WBM）的毫米波传输新技术。WBM的区别特征在于，比特信息是通过信号光束的传播衰减差异来传输的，而不是由原始信号光束携带的。在保持毫米波频率的高数据传输能力的同时，这一变化为物联网节点带来了高能效和低成本毫米波硬件实施的优势。它可以在没有移位器阵列和复杂信号处理（例如预编码甚至信道估计）的情况下进行部署。WBM的基本思想基于最近提出的空中调制（OTAM）方法，但有一些重大改进。通过在接入点（AP）节点上制定多个波束，WBM可以通过空分复用实现多用户访问，与OTAM相比，这大大提高了频谱效率。此外，通过在IoT节点和中央AP之间对准多个波束，WBM提供了强大的传输能力并允许进行高阶调制。因此，