Over-the-air signaling in cellular communication systems

Cellular communication systems have undergone a revolutionary change in the past decade. Emerging new technologies have completely transformed the cellular world and are constantly improving the data throughput of today's cellular systems. However, one important factor that is often overlooked is the wireless or OTA signaling used in a cellular system. In fact, OTA signaling is not only the supporting structure of a cellular communication system, which directly affects the stability, reliability, and efficiency of the system, but also an essential factor in the materialization of these new technologies. This article addresses the important roles and key design aspects of OTA signaling in today's cellular communication systems. In particular, we describe the physical design of OTA signaling in various application scenarios to meet specific requirements, such as robustness, latency, coverage, overhead, and detection complexity. We demonstrate how these design aspects are applied in the design of OTA signaling in an LTE system. Finally, we use a special design example to further illustrate the fundamentals of the OTA signaling design presented in this article.