航空学报 > 2023, Vol. 44 Issue (12): 327775-327775   doi: 10.7527/S1000-6893.2022.27775

北斗L/C双波段导航信号调制方式及性能评估

倪育德, 易茉涵, 刘瑞华()   

  1. 中国民航大学 电子信息与自动化学院,天津  300300
  • 收稿日期:2022-07-07 修回日期:2022-08-07 接受日期:2022-09-06 出版日期:2022-09-14 发布日期:2022-09-13
  • 通讯作者: 刘瑞华 E-mail:rhliu_cauc@163.com
  • 基金资助:
    国家重点研发项目(2016YFB0502402)

L/C dual-band navigation signal modulation mode and performance evaluation of BeiDou system

Yude NI, Mohan YI, Ruihua LIU()   

  1. College of Electronic & Information and Automation,Civil Aviation University of China,Tianjin  300300,China
  • Received:2022-07-07 Revised:2022-08-07 Accepted:2022-09-06 Online:2022-09-14 Published:2022-09-13
  • Contact: Ruihua LIU E-mail:rhliu_cauc@163.com
  • Supported by:
    National Key Research and Development Project(2016YFB0502402)

摘要:

大间隔L/C双频段导航可显著提高定位精度和鲁棒性,将成为未来高精度卫星导航系统的发展趋势。为降低双频终端的复杂度,设计了一种通用调制方式,使其既满足L/C波段的频谱兼容性约束,又具有良好的导航性能。提出将正交频分复用-连续相位调制(OFDM-CPM)联合调制方式应用于L/C双波段导航。选取调制指数h=0.5、关联长度L与OFDM-CPM符号数一致的OFDM-CPM信号作为L/C双波段候选导航信号,设定双频频点,并对包括兼容性、码跟踪精度、抗多径干扰在内的基础导航性能指标进行评估。研究表明:在L波段,OFDM-CPM(15)具有优良的码跟踪性能和抗多径能力,且更易与其他候选信号共存;在C波段,OFDM-CPM(10)能很好兼顾C波段信号的带外约束性和导航性能要求,在码跟踪精度与抗多径干扰方面表现最佳,为未来北斗系统导航信号体制的设计提供一种选择。

关键词: L/C双波段导航, 调制方式, 正交频分复用(OFDM), 连续相位调制(CPM), 导航性能

Abstract:

Large interval L/C dual-band navigation can significantly improve positioning accuracy and robustness, and will become the development trend of high precision satellite navigation system in the future. To reduce the complexity of dual-frequency terminals, a universal modulation scheme is designed, which not only meets the spectrum compatibility constraints of L/C-band, but also has good navigation performance. A combination of Orthogonal Frequency Division Multiplexing-Continuous Phase Modulation (OFDM-CPM) is proposed for L/C dual-band navigation. OFDM-CPM signals with the modulation index h=0.5 and the correlation length L consistent with the number of OFDM-CPM symbols are selected as L/C dual-band candidate navigation signals. Dual-frequency points are set, and the basic navigation performance indicators including compatibility, code tracking accuracy and anti-multipath interference are evaluated. The results show that in L-band, OFDM-CPM(15) has excellent code tracking performance and anti-multipath ability, and is easier to coexist with other candidate signals. In C-band, OFDM-CPM(10) can well take into account the out-of-band constraint and navigation performance requirements of C-band signals, and has the best performance in code tracking accuracy and anti-multipath interference, providing a choice for the design of navigation signal system of BDS in the future.

Key words: L/C dual-band navigation, modulation mode, Orthogonal Frequency Division Multiplexing (OFDM), Continuous Phase Modulation (CPM), navigation performance

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