Over-the-Air Computing for Wireless Data Aggregation in Massive IoT
Guangxu Zhu, Jie Xu, Kaibin Huang, Shuguang Cui
Abstract
Wireless data aggregation (WDA), referring to aggregating data distributed at devices (e.g., sensors and smartphones), is a common operation in 5G-and-beyond machine-type communications to support the Internet of Things (IoT), which lays the foundation for diversified applications such as distributed sensing, learning, and control. Conventional WDA techniques, which are designed in a task-agnostic manner separating communication and computation, encounter difficulty in accommodating the massive access under the limited radio resource and stringent latency constraints imposed by emerging applications or tasks (e.g, auto-driving). To address this issue, over-the-air computation (AirComp) is being developed as a new task-oriented solution for WDA by seamlessly integrating communication and computation. By exploiting the waveform superposition property of multiple access channels, AirComp turns the air into a computer for computing and communicating functions of distributed data at many devices, thereby allowing low-latency WDA over massive IoT networks. In view of growing interest in Air-Comp, this article provides a timely overview of the technology by introducing basic principles, discussing advanced techniques and applications, and identifying promising research opportunities.