Research And Implementation Of Navigation Signal Quality Assessment Technology

At present,human life is inseparable from the various services provided by the Global Satellite Navigation System(GNSS).The navigation satellite operating environment is very complicated,and the satellite load may work abnormally.In order to ensure timely knowledge of the working state of the satellite payload,it is necessary to monitor the quality of the terrestrial satellite signal to evaluate the working state of the satellite payload.With the development of navigation in various countries,new navigation signal systems are emerging,which brings about the problem of signal cochannel interference between different navigation systems,which makes the binary offset carrier(BOC)modulation method applied in satellite navigation systems.And the BOC modulation order adopted by the new system navigation signal is getting higher and higher.At present,China still needs a mature and stable monitoring and evaluation technology for the navigation signals of the new system.Based on the current development of navigation signal processing technology in the industry,this thesis mainly studies the navigation signal quality monitoring and evaluation technology of the most widely used BOC and binary phase shift keying(BPSK)modulation.The research mainly includes three modules: signal acquisition technology,tracking technology and navigation signal parameter measurement technology.Based on the algorithm research,this thesis transplants the signal acquisition and signal tracking algorithms to the FPGA platform,and transplants the navigation signal parameter measurement technology to the host computer software.Interoperability between the FPGA and the host computer through the Ethernet interface.In the signal acquisition technology,this thesis briefly introduces the mature acquisition method of BPSK modulation signal.For the multi-peak ambiguity problem of BOC modulated signals,this thesis introduces some existing algorithms.Aiming at the defects of existing algorithms,this thesis proposes a HBASSS algorithm based on the idea of GRASS algorithm.In the signal tracking technology.In the signal tracking technology,this thesis introduces the mature BPSK modulation signal tracking method and explains the signal tracking method of HBASS algorithm in detail.In the navigation signal parameter measurement technology part,this thesis studies the measurement algorithm of navigation signal power,carrier frequency,pseudorange and phase consistency of carrier and spread code.Aiming at the problem that the RF carrier phase is difficult to observe after mixing the RF signal at the antenna end,this thesis designs a simple and easy algorithm for measuring the phase consistency of carrier and spread code.The finally implemented hardware system platform can complete the long-term monitoring and evaluation of the navigation signals based on BPSK and BOC modulation and the data recording function.This thesis gives a detailed introduction to the technical details of the platform.Compared with the existing domestic navigation signal monitoring technology research,this thesis solves the multi-peak ambiguity problem of high-order BOC modulated navigation signals proposed in recent years.The research in this thesis is complementary with the original GRASS algorithm,and forms a general algorithm for solving the multi-peak ambiguity problem of any even-order BOC modulated signal.