Title: Coherency evaluation of GNSS MBOC pilot and data signal in joint tracking
Authors: Xue Wang; Yao Guo; Zhenghong Zhu; Xiaochun Lu
Addresses: National Time Service Center, Chinese Academy of Sciences, Xi'an, 710600, China; Key Laboratory of Precision Navigation, Positioning and Timing Technology, Chinese Academy of Sciences, Xi'an, Shaanxi 710600, China; School of Electronic and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 101408, China ' National Time Service Center, Chinese Academy of Sciences, Xi'an, 710600, China; Key Laboratory of Precision Navigation, Positioning and Timing Technology, Chinese Academy of Sciences, Xi'an, Shaanxi 710600, China; School of Electronic and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 101408, China ' Department of Mechanical Engineering, York University, M3J 1P3, Canada ' National Time Service Center, Chinese Academy of Sciences, Xi'an 710600, China; Key Laboratory of Precision Navigation, Positioning and Timing Technology, Chinese Academy of Sciences, Xi'an, Shaanxi 710600, China
Abstract: The MBOC signal uses a modulation in which the pilot and the data signals are separated. However, these modulation methods have evolved a variety of joint receiving algorithms. The paper introduces the optimal design strategy for MBOC signal joint tracking, in which the amplitude and phase outputs in the loop phase discriminator are linear composite with the weight coefficients. According to the different modulations of each GNSS system, these composite coefficients are determined by the signals modulation phase relationship and power relationship. Through the BDS data verification, the advantages of joint tracking are demonstrated. The influences of signal coherency in the joint tracking process are analysed. The coherencies of between each signal code and code-to-carrier in GPS L1C, BDS B1C, and GALILEO E1C signals are evaluated by high carrier-to-noise ratio signal, which is acquired with the National Time Service Center CAS 40-metre antenna signal in space quality assessment system. The results verify the GNSS signal in space meets joint tracking requirements.
Keywords: GNSS MBOC signal; joint tracking; codes coherency; signal in space quality assessment; code-to-carrier coherency.
DOI: 10.1504/IJSPACESE.2020.109747
International Journal of Space Science and Engineering, 2020 Vol.6 No.1, pp.49 - 63
Received: 07 Sep 2019
Accepted: 29 Oct 2019
Published online: 22 Sep 2020 *