Small satellites in low-Earth orbit (LEO) attract much attention from both industry and academia. The latest production and launch technologies constantly drive the development of LEO constellations. However, wideband signals, except text messages or voice in a few Kbps, cannot be transmitted directly from a LEO satellite to a standard mobile cellular phone due to the insufficient link budget. The current LEO constellation network has to use an extra ground device to receive the signal from the satellite first and then forward the signal to the user equipment (UE). To achieve direct network communications between LEO satellites and UE, in this article, we propose a novel distributed beamforming technology based on the superposition of electromagnetic (EM) waves radiated from multiple satellites that can significantly enhance the link budget. EM full-wave simulation and Monte Carlo simulation results are provided to verify the effectiveness of the proposed method. The simulation results show a nearly 6-dB enhancement using two radiation sources and an almost 12-dB enhancement using four sources. The received power enhancement could be doubled compared to the diversity gain in multiple-input, single-output (MISO). Furthermore, other practical application challenges, such as synchronization and the Doppler effect, are also presented.

中文翻译：

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增强卫星到电话链路预算：一种使用分布式波束成形的方法

低地球轨道（LEO）小型卫星引起了工业界和学术界的广泛关注。最新的生产和发射技术不断推动LEO星座的发展。然而，由于链路预算不足，除了几 Kbps 的文本消息或语音之外，宽带信号无法直接从 LEO 卫星传输到标准移动蜂窝电话。目前的LEO星座网络必须使用额外的地面设备首先接收来自卫星的信号，然后将信号转发到用户设备（UE）。为了实现LEO卫星和UE之间的直接网络通信，在本文中，我们提出了一种基于多颗卫星辐射的电磁（EM）叠加的新型分布式波束成形技术，可以显着提高链路预算。提供了电磁全波仿真和蒙特卡罗仿真结果来验证所提方法的有效性。仿真结果显示，使用两个辐射源可实现近 6 dB 的增强，使用四个辐射源可实现近 12 dB 的增强。与多输入、单输出 (MISO) 中的分集增益相比，接收功率增强可以加倍。此外，还提出了其他实际应用挑战，例如同步和多普勒效应。