低轨卫星信号捕获与跟踪技术综述

A Survey on Low Earth Orbit Satellite Signal Acquisition and Tracking Technology

低轨(Low Earth Orbit,LEO)卫星互联网相较于地面网络有更大的网络覆盖范围与更强的网络稳定性,有利于实现全球立体无缝网络覆盖,是未来6G网络重要的发展趋势。低轨卫星相较于中高轨卫星具有更高的运行速度,因此,低轨卫星信号具有更大的多普勒频移和动态特性,而低轨卫星信号的高精度捕获与跟踪是低轨卫星通信的基础。随着相控阵天线在低轨卫星和卫星终端上的推广应用,多波束和跳波束技术也为信号的捕获与跟踪带来挑战。从低轨卫星信号互联网的信号特点出发,提出了信号捕获与跟踪过程中的技术挑战,重点阐述了现有捕获与跟踪方法的基本原理与适用范围,探讨了低轨卫星网络中信号捕获与跟踪技术的未来发展方向。

Compared with terrestrial networks,Low Earth Orbit(LEO) has larger network coverage and stronger network stability,which is beneficial to the realization of global three-dimensional seamless network coverage,and is an important direction trend of the future 6G network.LEO satellites have higher operating speeds compared to medium and high Earth orbit satellites.Therefore,LEO satellite signals have larger Doppler frequency shifts and dynamic characteristics.The high-precision acquisition and tracking of LEO satellite signals is the foundation of integrated satellite-terrestrial communication.With the promotion and application of phased array antennas in LEO satellites and satellite terminals,multi-beam and hopping beam technologies also pose challenges for signal acquisition and tracking.This paper presents technical challenges in signal acquisition and tracking in view of signal characteristics of LEO satellite signal,focuses on basic principles and scope of application of existing acquisition and tracking methods,and finally discusses future development direction of signal acquisition and tracking technology in LEO satellite network.