中国空间科学技术

中国空间科学技术 ›› 2025, Vol. 45 ›› Issue (6): 152-159.doi: 10.16708/j.cnki.1000-758X.2025.0097

• 论文 • 上一篇    

一种抗多普勒低轨导航增强信号

严涛1,*，李天1，张明欢2，王瑛1，王方舟2，田广宇2，边朗1   

  1. 1.中国空间技术研究院西安分院，西安710000
    2.中国星网网络系统研究院有限公司，北京100000
  • 收稿日期:2024-12-08 修回日期:2025-04-30 录用日期:2025-05-10 发布日期:2025-11-17 出版日期:2025-12-01

An LEO navigation augmentation signal with anti-Doppler

YAN Tao1,*，LI Tian1，ZHANG Minghuan2，WANG Ying1，WANG Fangzhou2，TIAN Guangyu2，BIAN Lang1   

  1. 1.China Academy of Space Technology (Xi’an)，Xi’an 710000, China
    2.China Satellite Network System Co., Ltd.，Beijing 100000，China
  • Received:2024-12-08 Revision received:2025-04-30 Accepted:2025-05-10 Online:2025-11-17 Published:2025-12-01

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摘要： 低轨导航增强系统是当前卫星导航领域的发展热点，通过播发专用的低轨导航增强信号加快精密单点定位收敛速度是其主要发展方向。然而，低轨卫星轨道高度低，运动速度快，导致低轨导航增强信号多普勒范围超过-30～30kHz，远高于传统的全球卫星导航系统信号的-5～5kHz，如何快速捕获低轨导航增强信号成为一个难点。针对该问题，提出一种具有抗多普勒特性的低轨导航增强信号，该信号具有恒包络特性，便于信号生成。更重要的是，该信号在多普勒维度具有多峰相关特性，能够实现快速捕获。针对该信号，设计了“两步法”实现快速捕获：第一步在-5～5kHz多普勒范围内进行信号捕获，第二步利用多普勒维度的多峰相关特性，对多普勒维度的模糊度进行捕获，确定最终的多普勒与码相位捕获结果。仿真结果表明，设计的抗多普勒低轨导航增强信号，捕获阶段多普勒维度只需搜索-5～5kHz范围，比常规的低轨导航增强信号捕获速度提升6倍以上，捕获效率与传统的GNSS信号相当。提出的抗多普勒低轨导航增强信号，其捕获时间不随多普勒范围变化而变化，具有抗多普勒特性，可为低轨导航增强信号的设计提供参考。

关键词: 低轨导航增强信号, 抗多普勒, 信号捕获, 恒包络, 全球卫星导航系统

Abstract: The low earth orbit (LEO) navigation augmentation system is currently a hot topic in the field of global satellite navigation system (GNSS), and its main development direction is to accelerate the convergence speed of precise point positioning (PPP) by broadcasting dedicated LEO navigation augmentation signal. However, LEO satellites have lower orbital heights and faster motion speeds, resulting in a Doppler range of over ±30kHz for LEO navigation augmentation signal, much higher than the ±5kHz range of traditional GNSS signals. How to fast acquire the LEO navigation augmentation signal has become a challenge. An LEO navigation augmentation signal with anti-Doppler characteristics is proposed to address this issue. The proposed signal has the constant envelope characteristic, which is beneficial for signal generation. More importantly, the proposed signal exhibits the multi-peak correlation properties in the Doppler dimension, enabling fast acquisition. For the proposed signal, a two-step method is designed to achieve fast acquisition: the first step is to acquire the signal within the ±5kHz Doppler range, and the second step is to utilize the multi peak correlation characteristics of the Doppler dimension to determine the ambiguity of the Doppler dimension and obtain the final Doppler and code phase. The simulation results show that the designed LEO navigation augmentation signal only needs to search for the Doppler dimension within ±5kHz range during the acquisition phase, which is more than 6 times faster than the acquisition speed of the conventional LEO navigation augmentation signal, and that the acquisition efficiency is comparable to traditional GNSS signals. The proposed LEO navigation augmentation signal has the anti-Doppler characteristics, and its acquisition time does not change with the Doppler range. It can provide reference for the design of LEO navigation augmentation signal.

Key words: LEO navigation augmentation signal, anti-Doppler, signal acquisition, constant envelope, global navigation satellite system