Multiplexing modulation design optimization and quality evaluation of BDS-3 PPP service signal  

作　　者：Cheng Liu Zheng Yao Dun Wang Weiguang Gao Tianxiong Liu Yongnan Rao Dongjun Li Chengeng Su 

机构地区：[1]Beijing Institute of Tracking and Telecommunication Technology,Beijing 100094,China [2]Department of Electronic Engineering,Tsinghua University,Beijing 100084,China [3]Space Star Technology,Beijing 100095,China [4]Beijing Institute of Spacecraft System Engineering,Beijing 100094,China [5]National Time Service Center,Academy of Sciences,Xi’an 710600,China

出　　处：《Satellite Navigation》2022年第1期47-59,I0003,共14页卫星导航（英文）

基　　金：supported by China Association for Science and Technology(2019QNRC001);Young Innovation Foundation of Beijing National Research Center for Information Science and Technology(under Grant BNR2021RC01015);National Natural Science Foundation of China(Nos.42074044 and 61771272).

摘　　要：The Precise Point Positioning(PPP)service of BeiDou-3 Navigation Satellite System(BDS-3)is implemented on its Geostationary Earth Orbit(GEO)satellites.However,its signal design is limited by the actual power of satellite and other conditions.Furthermore,the design needs to fully consider the compatibility of diferent service phases.Starting from the actual state of the BDS-3 GEO satellite,this paper studies the multiplexing modulation of the BDS PPP service signal that is based on the Asymmetric Constant Envelope Binary Ofset Carrier(ACE-BOC)technique and proposes several feasible schemes for this signal.Comparison and optimization of these techniques are made from the aspects of transmission efciency,multiplexing efciency,and service forward compatibility.Based on the Type-III ACE-BOC multiplexing modulation technique,phase rotation and intermodulation reconstruction techniques are proposed to suppress the intermodulation interference issue.Finally,a signal based on improved ACE-BOC multiplexing is designed.The quality of the proposed signal was continuously monitored and tested using large-diameter antennas.The evaluation results show that the power spectrum deviation of the signal is 0.228 dB,the correlation loss is 0.110 dB,the S-curve slope deviation is 1.558%on average,the average length diference between the positive/negative chip and the ideal chip is only 0.0006 ns,and the coherence between the carrier and the pseudo code is 0.082°.All quality indicators are satisfactory,indicating that the proposed signal multiplexing modulation technique is an ideal solution that meets all the requirements of the design constraints,and can achieve efcient information broadcasting and forward compatibility of the BDS PPP service.

关 键 词：BEIDOU Precise point positioning Constant envelope multiplexing ACE-BOC Inter-modulation construction 

分 类 号：P228.4[天文地球—大地测量学与测量工程]