Enhancement of Satellite-to-Phone Link Budget by Using Distributed Beamforming

TL;DR

This paper introduces a distributed beamforming technique for LEO satellites that significantly improves the link budget, enabling direct satellite-to-phone communication without additional ground infrastructure.

Contribution

The paper proposes a novel electromagnetic distributed beamforming method based on superposition from multiple satellites, verified through simulations showing substantial power enhancements.

Findings

Nearly 6 dB power gain with two sources

Almost 12 dB power gain with four sources

Potential to double received power compared to MISO diversity

Abstract

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, the wideband signal, except text messages, cannot be transmitted directly from an 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, 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 in this paper. 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 and Single-Output (MISO). Furthermore, other practical application challenges, such as the synchronization and Doppler effect, are also presented.